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 .
Response to Amendment
The following addresses Applicant’s remarks/amendments dated 21 August 2026.
Claims 1, 5, 8-9, and 13 were amended; Claim 16 was added; no claims were cancelled; therefore Claims 1-16 are pending in the current application and will be addressed below.
Response to Argument
Applicant’s arguments filed 21 August 2026 in response to the previous Office Action have been fully considered.
Applicant’s arguments with respect to Claim 1 on pages 8 and 9 have been fully considered but are not persuasive.
Applicant argues that Claim 1 requires a “single detector unit,” whereas Keller utilizes separate photodiodes (PD1 and PD2) on polarization-dependent channels. Under the broadest reasonable interpretation, the term “detector unit” is not restricted to a single, isolated photodiode, but broadly encompasses the overall detection assembly and receiver architecture as a whole. In Keller, elements 41 and 42 (PD1 and PD2 respectively), along with their associated coupling and receiving components, function together as a single, unified detector unit (receiver system) within the apparatus to capture the optical radiation and convert it to detection signals. The individual photodiodes PD1 and PD2 are sub-components of this single overarching detector unit.
Applicant argues that Keller operates in an optical domain with polarization components, which does not suggest the utilization of an electronic/time/frequency domain as recited in the amended claims. While Keller accomplishes primary beam interference in the optical domain prior to detection, You-jian teaches processing an optical receiver in the time/frequency domain. Applying You-jian’s time/frequency domain electronic signal processing to the electrical output generated by Keller’s optical detection stage would have been obvious to a person of ordinary skill in the art to optimize signal processing and improve fringe contrast.
Applicant’s arguments with respect to Claim 9 on page 10 have been fully considered but are not persuasive.
Applicant argues that You-jian employs echo signals and electrical detection signals, rendering it incompatible with Keller where signals are polarization-dependent. Examiner respectfully disagrees. The test for obviousness under 35 U.S.C. 103 is not whether the physical components of a secondary reference can be bodily incorporated into the primary reference, but rather what the combined teachings would have suggested to a person of ordinary skill in the art. See In re Keller, 642 F.2d 413, 425, 208 USPQ 871, 881 (CCPA 1981). While Keller utilizes polarization optics prior to detection, upon striking the photodiodes (PD1 and PD2) of Keller’s detection unit, the optical radiation is transduced into an electrical detection signal. You-jian teaches time/frequency domain self-interference processing performed on such electrical detection signals downstream of optical detection. Combining You-jian’s downstream electronic signal processing with Keller’s detector unit does not alter or disrupt Keller’s optical front-end.
Applicant also argues that the combination of Keller and You-jian would not reasonably and objectively lead to the instant amended claim set. However, a person of ordinary skill in the art seeking to enhance measurement resolution and fringe contrast in Keller’s dual-comb system would naturally apply You-jian’s downstream electrical self-interference processing to the electrical output of Keller’s detector unit. Doing so represents the application of a known electronic processing technique to a known optical detection system to yield predictable results.
Applicant’s arguments with respect to Claim 5 on page 8 have been fully considered. Applicant’s amendments overcome the indefiniteness rejection under 35 U.S.C. 112(b). Accordingly, the rejection of Claim 5 under 35 U.S.C. 112(b) is withdrawn.
Applicant’s arguments with respect to Claim 8 on page 8 have been fully considered. Applicant’s amendments overcome the objection. As such, the informalities objection of Claim 8 is withdrawn.
Applicant’s argument with respect to Claims 11 and 14-15 on pages 9-10 have been fully considered but are not persuasive.
Applicant argues that Claims 11 and 14-15 incorporate limitations of base claims distinguished above. As discussed above, the rejection of Claim 1 is maintained under 35 U.S.C. 103. The additional limitations of Claims 11 and 14-15 regarding optical fiber routing and controller/software execution represent standard optical routing and digital signal processing techniques well within the routine skill of a person of ordinary skill in the art.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action.
Claims 1 recites “superposition means configured to superimpose the first pulsed beam (PB1) and the second pulsed beam (PB2) into a superimposed beam (SB)”
The “superposition means” are described in paragraph [0026] as “inlcud[ing] at least one of a beam splitter or an optical combiner… other optical means suitable for overlapping the first pulsed beam and the second pulsed beam may be used.”
The “superposition means” are therefore interpreted in view of the specification as any device/structure capable of performing the function.
Because these claim limitations are being interpreted under 35 U.S.C. 112(f) or pre-AIA
35 U.S.C. 112, sixth paragraph, they are being interpreted to cover the corresponding structure
described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have these limitations interpreted under 35 U.S.C. 112(f)
or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to
avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph
(e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient
showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed
function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C.
112, sixth paragraph.
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 (i.e., changing from AIA to pre-AIA ) 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 1-15 are rejected under 35 U.S.C. 103 as being unpatentable over Keller et al. (US 2025/0306204 A1) in view of You-jian et al. (CN 114047521 A).
Regarding Claim 1, Keller teaches an apparatus for distance measurement ([0002] laser-based distance ranging (Light Detection and Ranging LiDAR) devices), comprising:
a pulsed beam source configured to emit a first pulsed beam (PB1) having a first pulse repetition rate and a second pulsed beam (PB2) having a second pulse repetition rate different from the first pulse repetition rate ([0013] Generating a dual comb radiation that includes a first radiation portion with a train of first radiation pulses having a first pulse repetition frequency and a second radiation portion with a train of second radiation pulses having a second pulse repetition frequency, which is slightly different from the first pulse repetition frequency… [0016] Combining the first signal radiation portion (having the first pulse repetition frequency) and the second signal radiation portion (having the second pulse repetition frequency) into a combined signal radiation… [0017] Directing the combined signal radiation onto an object);
superposition means configured to superimpose the first pulsed beam (PB1) and the second pulsed beam (PB2) into a superimposed beam (SB) ([0016] Combining the first signal radiation portion (having the first pulse repetition frequency) and the second signal radiation portion (having the second pulse repetition frequency) into a combined signal radiation… [0034]-[0037] The step of combining may be made, for example by a polarization combiner, in a manner that shares of the combined signal radiation due to the first signal radiation portion have a first polarization and shares of the combined signal radiation due the second signal radiation portion have a second polarization different from the first polarization… Polarization combiners that produce a combined beam with orthogonal polarizations from two polarized beams);
a beam splitting unit configured to split the superimposed beam (SB) into a reference beam (RB) ([0047] will generate a reference signal that is subject to the steps of splitting into the first and second signal portions and of superimposing together with the signal that is thrown back from the object) and a measurement beam (MB) ([0019]-[0020] Splitting the signal into a first signal portion and a second signal portion. Superimposing, by the first radiation splitter, the first signal portion with the second local oscillator radiation portion to generate a first measurement signal);
a single detector unit ([0070] While the parts that are coupled into the input ports connected to the frequency dual comb radiation source may be prevented from getting back into the radiation source by optional optical isolators, the parts that reach the respective other input port reaches the first/second detector, so that the first detector, by its connection to the remaining input port of the first beam splitter, is arranged to receive the first measurement signal whereas the second detector receives the second measurement signal Examiner Note: Keller alludes to the broadest reasonable interpretation, explained in section 5 above, by referring to the detector pair as “first/second” detector) configured to:
receive the reference beam (RB) after it has traveled along a reference beam path ([0047] in the post-processing this can be used to determine the distance as a distance between the reflection of the reference signal and the reflection by the structure) and the measurement beam (MB) after it has traveled along a distance measurement path to an object ([0018] Receiving a signal thrown back from the object irradiated by the combined signal radiation) and provide a detection signal corresponding to the received reference beam (RB) and measurement beam (MB) ([0031] The generation of the first/second measurement signals may include an optical-to-electric conversion, for example by a first/second photodiode), and
provide a reception signal indicative of a distance (d) to the object based on the received reference beam (RB) and the received measurement beam (MB) ([0074] This data acquisition system is a post-processing unit that is equipped to analyze the first and second measurement signals. The post-processing unit may include at least one analog-to-digital converter as well as a software for determining, from the digitized signal, the distance) by interfering the detection signal with itself ([0022]-[0023] Determining a distance to the object from the first and second measurement signals. In this, the superimposing of the respective signal portions with the local oscillator portions will cause interference for components having the same polarization, thus the first and second measurement signals are interference signals).
Keller is not relied upon as teaching an interference unit configured to interfere the detection signal with itself to obtain the reception signal, wherein the detector unit is configured to provide the detection signal in a time domain and/or a frequency domain.
However, You-jian teaches an interference unit configured to interfere the detection signal with itself to obtain the reception signal ([P. 14, ll. 16-29] object 8 set the position… so as to reduce the power difference between the reference echo signal c2 and the detection echo signal c1… convenient for detecting and processing the subsequent signal, improving interference fringe contrast), wherein the detector unit is configured to provide the detection signal in a time domain and/or a frequency domain ([P. 15, ll. 2-8] to obtain the first electrical detection signal e and the second electrical detection signal g for low-pass filtering, filtering the interference signal, the filtered first electrical detection signal e enters the first data acquisition module 11A and the first signal processing module 12A, the filtered second electrical detection signal g enters the second data acquisition module 11B and the second signal processing module 12B, and analyzes to obtain the flight time and spatial distance value of the pulsed light, improving the resolution precision Examiner Note: Low-pass filtering is well established in the art of signal processing as a fundamental time/frequency domain operation).
Keller and You-jian are considered to be analogous to the claimed invention because they are both in the same field of LiDAR devices and optical signal detection systems. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the receiver architecture and detection unit of Keller to include the downstream time/frequency domain self-interference electronic signal processing (including low-pass filtering) of You-jian with a reasonable expectation of success. This modification would have been motivated by the desire to enhance measurement resolution precision and improve interference fringe contrast while reducing power differences between reference and detection signals. By integrating You-jian’s teaching of downstream electronic self-interference filtering into Keller’s electrical detection output, the system can optimize electrical signal processing downstream of optical detection without altering or disrupting the optical front-end. A person of ordinary skill in the art would recognize that applying a known electronic processing technique to a known optical detection system would yield the predictable result of improved distance determination precision and enhanced signal quality.
Regarding Claim 2, Keller teaches an analysis unit configured to determine the distance (d) to the object based on the reception signal ([0047] in the post-processing this can be used to determine the distance as a distance between the reflection of the reference signal and the reflection by the structure), wherein:
the analysis unit is further configured to determine a velocity of the object and/or the apparatus based on the determined distance (d) to the object ([0032] In contrast to the latter, the approach according to the present invention, which includes splitting both combs, allows to generate the first and second measurement results simultaneously so that the method can for example also be used to determine the distance—and/or velocity—of moving objects); and/or
the analysis unit is configured for time synchronization based on the determined distance (d) to the object; and/or
the analysis unit is configured for vibration measurements based on the determined distance (d) to the object.
Regarding Claim 3, Keller teaches that the pulsed beam source include:
a first pulsed beam source configured to emit the first puled beam (PB1) having the first pulse repetition rate; and
a second pulsed beam source configured to emit the second pulsed beam having the second pulse repetition rate ([0013] Generating a dual comb radiation that includes a first radiation portion with a train of first radiation pulses having a first pulse repetition frequency and a second radiation portion with a train of second radiation pulses having a second pulse repetition frequency, which is slightly different from the first pulse repetition frequency),
in particular wherein the first pulsed beam source and the second pulsed beam source are separate pulsed beam sources ([0084] Also dual comb laser sources that include two lasers that are synchronized in a suitable manner are known and can be used for the present invention).
Regarding Claim 4, Keller teaches that the pulsed beam source is a pulsed laser beam source, and wherein the first pulsed beam (PB1) is a first pulsed laser beam and the second pulsed beam (PB2) is a second pulsed laser beam ([0084] The device shown in FIG. 1 includes a dual-comb (laser) radiation source 1 emitting two radiation portions 11, 12, each being a train of laser pulses, with the pulse repetition frequencies being slightly offset between the two trains).
Regarding Claim 5, Keller teaches that the first pulse repetition rate is selected from one or the following: 1MHz or larger, or 10MHz or larger, or 100MHz or larger, or 1GHz or larger ([0051] The repetition rate of the dual comb may be chosen, especially by choosing the appropriate cavity length, depending on the specific needs. It may for example be between 50 MHz and 10 GHz, especially between 250 MHz and 2 GHz);
the second pulse repetition rate is selected from one of the following: 1MHz or larger, or 10MHz or larger, or 100MHz or larger, or 1GHz or larger ([0051] The repetition rate of the dual comb may be chosen, especially by choosing the appropriate cavity length, depending on the specific needs. It may for example be between 50 MHz and 10 GHz, especially between 250 MHz and 2 GHz);
a difference between the first pulse repetition rate and the second pulse repetition rate is selected from one of the following: 1kHz or larger, 10kHz or larger, or 100kHz or larger ([0013] Generating a dual comb radiation that includes a first radiation portion with a train of first radiation pulses having a first pulse repetition frequency and a second radiation portion with a train of second radiation pulses having a second pulse repetition frequency, which is slightly different from the first pulse repetition frequency Examiner Note: Choosing “slightly different” frequencies within the acceptable range of [0051] would yield a difference of greater than 1kHz); and
a difference between the first pulse repetition rate and the second pulse repetition rate is selected from one of the following: 15% or less, 10% or less, 5% or less, or 1% or less of the first pulse repetition rate or the second pulse repetition rate ([0013] Generating a dual comb radiation that includes a first radiation portion with a train of first radiation pulses having a first pulse repetition frequency and a second radiation portion with a train of second radiation pulses having a second pulse repetition frequency, which is slightly different from the first pulse repetition frequency Examiner Note: Choosing “slightly different” frequencies within the acceptable range of [0051] would yield a difference of less than 15%).
Regarding Claim 6, Keller teaches that the superposition means includes at least one of a beam splitter and an optical combiner ([0034]-[0037] The step of combining may be made, for example by a polarization combiner, in a manner that shares of the combined signal radiation due to the first signal radiation portion have a first polarization and shares of the combined signal radiation due the second signal radiation portion have a second polarization different from the first polarization… Polarization combiners that produce a combined beam with orthogonal polarizations from two polarized beams).
Regarding Claim 7, Keller teaches that the beam splitting unit includes at least one of a beam splitter, an optical combiner, an optical circulator, a density filter, a reference unit configured for partial reflection and transmission, and combinations thereof ([0030] The first and second radiation splitters may be constituted by distinct, dedicated beam splitting devices).
Regarding Claim 8, Keller teaches that the beam splitting unit includes:
a first optical unit configured for the transmission of the superimposed beam (SB) ([0070] the first radiation splitter superimposes the first signal portion with the second local oscillator radiation portion to generate a first measurement signal); and
a second optical unit configured for the partial reflection and partial transmission of the superimposed beam (SB) having passed through the first optical unit ([0087]-[0089] The combined signal radiation that consists of the first and second signal radiation portions 21, 22 is used to sample the distance d between the end facet R of the fiber tip 9 and the object (target T) 10… the end facet R of the fiber tip 9 serves as a reference plane in that a portion of the combined signal radiation is reflected by it),
wherein the first optical unit is further configured for reflection of a portion of the superimposed beam (SB) which has been reflected by the second optical unit, and
wherein the detector unit is configured to receive the portion of the superimposed beam (SB) which has been reflected by the first optical unit ([0070] the parts that reach the respective other input port reaches the first/second detector, so that the first detector, by its connection to the remaining input port of the first beam splitter, is arranged to receive the first measurement signal whereas the second detector receives the second measurement signal),
in particular wherein the second optical unit is configured for the transmission of the measurement beam (MB) after it has traveled along the distance measurement path to the object ([0087] The combined signal radiation that consists of the first and second signal radiation portions 21, 22 is used to sample the distance d between the end facet R of the fiber tip 9 and the object (target T) 10).
Regarding Claim 9, Keller teaches that the detector unit includes:
at least one optical detector configured to receive the reference beam (RB) and the measurement beam (MB) ([0070]-[0073] the first detector, by its connection to the remaining input port of the first beam splitter, is arranged to receive the first measurement signal… The detectors may be photodiodes), wherein the detector unit is configured to provide the detection signal corresponding to the reference beam (RB) and the measurement beam (MB) received at the at least one optical detector ([0031] the first detector, by its connection to the remaining input port of the first beam splitter, is arranged to receive the first measurement signal).
Regarding Claim 10, Keller teaches that the pulsed beam source is configured to provide pulsed beams in a predetermined wavelength range, wherein the pulsed beams in the predetermined wavelength range are configured for distance measurements to different measurement points ([0051]-[0054] The dual comb radiation will be in the near infrared or visible range, with wavelengths that for example lay in the range of between 0.3 μm and 2 μm… The pulse repetition rate difference between the two combs may be matched to the required measurement distance to the object, which is application dependent. The difference in the repetition rates Δf.sub.rep may for example be set so that using the Vernier technique one is able to resolve up to the required measurement distance. The maximum distance without ambiguity is c/(2*Δf.sub.rep). For many applications, it is ideal if the value c/(2*Δf.sub.rep) exceeds the required distance but not by too much for best performance, for example not more than by a factor 2 or 3. In embodiments, therefore, the following inequality may hold: c/(2*Δf.sub.rep)/3<d<c/(2*Δf.sub.rep); where d is the distance to be measured (which in many applications is approximately known)).
Regarding Claim 11, Keller teaches at least one first optical fiber connecting the pulsed beam source and the superposition means and at least one second optical fiber connecting the pulsed beam source and the superposition means ([0039] The dual comb radiation may be fiber-guided, i.e., at least after its generation it may be coupled into fibers, with the first and second radiation portions guided in different fibers), wherein the at least one first optical fiber is configured to guide the first pulsed beam (PB1) from the pulsed beam source to the superposition means, and wherein the at least one second optical fiber is configured to guide the second pulsed beam (PB2) from the pulsed beam source to the superposition means ([0038] As an alternative to using a polarization combiner for combining, it is also possible to use a polarization maintaining fiber coupler or a single-mode fiber coupler or the respective equivalent for free-space or waveguide set-ups. In these alternative embodiments, the first signal portion will include contributions by both combs. However, upon superposition with the second local oscillator portion), and/or
at least one third optical fiber connecting the superposition means and the beam splitting unit, wherein the at least one third optical fiber is configured to guide the superimposed beam (SB) from the superposition means to the beam splitting unit; and/or
at least one fourth optical fiber connecting the first optical unit and the second optical unit of the beam splitting unit to guide optical signals therebetween; and/or
at least one fifth optical fiber connecting the beam splitting unit and the detector unit to guide the reference beam (RB) and the measurement beam (MB) to the detector unit.
Even though Keller may not explicitly detail the exact terminal connections of each fiber to the “superposition means” as recited, it would have been obvious to a person of ordinary skill in the art to modify the teachings of Keller to configure the first and second fibers to guide the respective pulsed beams from the source to the superposition optics with a reasonable expectation of success. This modification would have been a matter of routine mechanical and optical arrangement, motivated by a desire to provide a flexible light delivery path between the laser source and the measurement optics.
Regarding Claim 12, Keller teaches that the pulsed beam source, the superposition means, the beam splitting unit and the detector unit are provided as a photonic integrated circuit ([0126] As an even further alternative, the device could also be implemented… by using integrated photonics on a chip).
Regarding Claim 13, Keller teaches a method for distance measurement ([0012]-[0022] The laser distance ranging method… includes… Determining a distance), comprising:
generating a first pulsed beam having a first pulse repetition rate and a second pulsed beam having a second pulse repetition rate different from the first pulse repetition rate ([0013] Generating a dual comb radiation that includes a first radiation portion with a train of first radiation pulses having a first pulse repetition frequency and a second radiation portion with a train of second radiation pulses having a second pulse repetition frequency);
superposing the first pulsed beam and the second pulsed beam into a superimposed beam ([0016] Combining the first signal radiation portion (having the first pulse repetition frequency) and the second signal radiation portion (having the second pulse repetition frequency) into a combined signal radiation);
splitting the superimposed beam into a reference beam ([0047] will generate a reference signal that is subject to the steps of splitting into the first and second signal portions and of superimposing together with the signal that is thrown back from the object) and a measurement beam ([0019]-[0020] Splitting the signal into a first signal portion and a second signal portion. Superimposing, by the first radiation splitter, the first signal portion with the second local oscillator radiation portion to generate a first measurement signal);
receiving, at a single detector unit ([0070] While the parts that are coupled into the input ports connected to the frequency dual comb radiation source may be prevented from getting back into the radiation source by optional optical isolators, the parts that reach the respective other input port reaches the first/second detector, so that the first detector, by its connection to the remaining input port of the first beam splitter, is arranged to receive the first measurement signal whereas the second detector receives the second measurement signal Examiner Note: Keller alludes to the broadest reasonable interpretation, explained in section 5 above, by referring to the detector pair as “first/second” detector), the reference beam after it has traveled along a reference beam path ([0047] in the post-processing this can be used to determine the distance as a distance between the reflection of the reference signal and the reflection by the structure) and the measurement beam after it has traveled along a distance measurement path to an object ([0018] Receiving a signal thrown back from the object irradiated by the combined signal radiation), and providing a detection signal, the detection signal corresponding to the received reference beam (RB) and measurement beam (MB) ([0031] The generation of the first/second measurement signals may include an optical-to-electric conversion, for example by a first/second photodiode);
generating a reception signal based on the received reference beam and the received measurement beam ([0074] This data acquisition system is a post-processing unit that is equipped to analyze the first and second measurement signals. The post-processing unit may include at least one analog-to-digital converter as well as a software for determining, from the digitized signal, the distance) by interfering the detection signal with itself; and
determining a distance to the object based on the reception signal ([0023] [0022] Determining a distance to the object from the first and second measurement signals.[0023] In this, the superimposing of the respective signal portions with the local oscillator portions will cause interference for components having the same polarization, thus the first and second measurement signals are interference signals).
Keller is not relied upon as teaching providing a detection signal in a time domain and/or a frequency domain.
However, You-jian teaches providing a detection signal in a time domain and/or a frequency domain ([P. 15, ll. 2-8] to obtain the first electrical detection signal e and the second electrical detection signal g for low-pass filtering, filtering the interference signal, the filtered first electrical detection signal e enters the first data acquisition module 11A and the first signal processing module 12A, the filtered second electrical detection signal g enters the second data acquisition module 11B and the second signal processing module 12B, and analyzes to obtain the flight time and spatial distance value of the pulsed light, improving the resolution precision Examiner Note: Low-pass filtering is well established in the art of signal processing as a fundamental time/frequency domain operation).
Keller and You-jian are considered to be analogous to the claimed invention because they are both in the same field of LiDAR devices and optical signal detection systems. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the receiver architecture and detection unit of Keller to include the downstream time/frequency domain self-interference electronic signal processing (including low-pass filtering) of You-jian with a reasonable expectation of success. This modification would have been motivated by the desire to enhance measurement resolution precision and improve interference fringe contrast while reducing power differences between reference and detection signals. By integrating You-jian’s teaching of downstream electronic self-interference filtering into Keller’s electrical detection output, the system can optimize electrical signal processing downstream of optical detection without altering or disrupting the optical front-end. A person of ordinary skill in the art would recognize that applying a known electronic processing technique to a known optical detection system would yield the predictable result of improved distance determination precision and enhanced signal quality.
Regarding Claim 14, Keller teaches a machine-readable medium comprising instructions executable by one or more processors to implement the method of claim 13 ([0074] software for determining… the distance in the manner described in the present text).
Although Keller does not explicitly recite a machine-readable medium comprising instructions executable by one or more processors to implement the entirety of the steps of the method of Claim 13, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Keller to include software including instructions to implement the entire method of claim 13 with a reasonable expectation of success. This modification would have been motivated by a desire to control the entire system.
Regarding Claim 15, Keller teaches a controller for an apparatus for distance measurement, comprising:
one or more processors ([0074] a data acquisition system to process the data… This data acquisition system is a post-processing unit); and
a memory coupled to the one or more processors and comprising instructions executable by the one or more processors to implement the method of claim 13 ([0074] The post-processing unit may include… software for determining… the distance in the manner described in the present text Examiner Note: The presence of software implies that there is memory to store said software).
Although Keller does not explicitly state that the controller implements the entirety of the steps of the method of Claim 13, it teaches that the software determines distance in a manner that encompasses the system’s core logic. It would have been obvious to a person of ordinary skill in the art to modify the teachings of Keller to include instructions to implement the entire method of Claim 13 with a reasonable expectation of success. This modification would have been motivated by a desire to centralize system control to ensure precise and repeatable distance measurements.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Keller et al. (US 2025/0306204 A1) in view of You-jian et al. (CN 114047521 A), as applied to Claims 1-15 above, and further in view of Boloorian et al. (US 12,535,586 B2).
Regarding Claim 16, Keller is not relied upon as teaching that the interference unit comprises a mixer or a saturated amplifier.
However, Boloorian teaches that the interference unit comprises a mixer or a saturated amplifier ([Col. 19, ll. 20-25] In FIG. 6B, the second multiplier 148 is configured to square the amplitude of the second data signal and to output a second multiplied data signal. Suitable first multipliers and/or second multipliers include, but are not limited to, RF mixers such as a Gilbert cell mixer).
Keller, as previously modified by You-jian, and Boloorian are considered to be analogous to the claimed invention because they are both in the same field of LiDAR devices and optical signal detection systems. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified Keller (as previously modified by You-jian) to include the RF mixer (such as a Gilbert cell mixer) as taught by Boloorian with a reasonable expectation of success. This modification would have been motivated by the desire to enable electronic signal multiplication and squaring of the detected signal’s amplitude downstream of the photodetector, thereby facilitating frequency conversion and signal extraction for accurate distance determination. By integrating Boloorian’s teaching of an RF mixer into the electrical processing chain of Keller (as previously modified by You-jian), the system can optimize electrical signal processing downstream of optical detection without altering or disrupting the optical front-end. A person of ordinary skill in the art would recognize that incorporating a standard electronic RF mixer into an electronic signal processing branch of a LiDAR receiver would yield the predictable result of reliably multiplying and mixing electrical data signals to enhance distance determination precision and signal quality.
Conclusion
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.
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/E.H.H./Patent Examiner, Art Unit 3645
/HELAL A ALGAHAIM/SPE , Art Unit 3645
