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 .
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the beam splitter of claim 9 and the plurality of measurement interferometers of claim 10 must be shown or the feature(s) canceled from the claim(s). No new matter should be entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Specification
The disclosure is objected to because of the following informalities:
The specification fails to include any headers delineating one section from the next in the specification as is common in United States practice. These headers should be added. Please find below reminders as to the arrangement and content of a patent application specification.
Appropriate correction is required.
The following guidelines illustrate the preferred layout for the specification of a utility application. These guidelines are suggested for the applicant’s use.
Arrangement of the Specification
As provided in 37 CFR 1.77(b), the specification of a utility application should include the following sections in order. Each of the lettered items should appear in upper case, without underlining or bold type, as a section heading. If no text follows the section heading, the phrase “Not Applicable” should follow the section heading:
(a) TITLE OF THE INVENTION.
(b) CROSS-REFERENCE TO RELATED APPLICATIONS.
(c) STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT.
(d) THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT.
(e) INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A READ-ONLY OPTICAL DISC, AS A TEXT FILE OR AN XML FILE VIA THE PATENT ELECTRONIC SYSTEM.
(f) STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR A JOINT INVENTOR.
(g) BACKGROUND OF THE INVENTION.
(1) Field of the Invention.
(2) Description of Related Art including information disclosed under 37 CFR 1.97 and 1.98.
(h) BRIEF SUMMARY OF THE INVENTION.
(i) BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S).
(j) DETAILED DESCRIPTION OF THE INVENTION.
(k) CLAIM OR CLAIMS (commencing on a separate sheet).
(l) ABSTRACT OF THE DISCLOSURE (commencing on a separate sheet).
(m) SEQUENCE LISTING. (See MPEP § 2422.03 and 37 CFR 1.821 - 1.825). A “Sequence Listing” is required on paper if the application discloses a nucleotide or amino acid sequence as defined in 37 CFR 1.821(a) and if the required “Sequence Listing” is not submitted as an electronic document either on read-only optical disc or as a text file via the patent electronic system.
Content of Specification
(a) TITLE OF THE INVENTION: See 37 CFR 1.72(a) and MPEP § 606. The title of the invention should be placed at the top of the first page of the specification unless the title is provided in an application data sheet. The title of the invention should be brief but technically accurate and descriptive, preferably from two to seven words. It may not contain more than 500 characters.
(b) CROSS-REFERENCES TO RELATED APPLICATIONS: See 37 CFR 1.78 and MPEP § 211 et seq.
(c) STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT: See MPEP § 310.
(d) THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT. See 37 CFR 1.71(g).
(e) INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A READ-ONLY OPTICAL DISC, AS A TEXT FILE OR AN XML FILE VIA THE PATENT ELECTRONIC SYSTEM: The specification is required to include an incorporation-by-reference of electronic documents that are to become part of the permanent United States Patent and Trademark Office records in the file of a patent application. See 37 CFR 1.77(b)(5) and MPEP § 608.05. See also the Legal Framework for Patent Electronic System posted on the USPTO website (https://www.uspto.gov/sites/default/files/documents/2019LegalFrameworkPES.pdf) and MPEP § 502.05
(f) STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR A JOINT INVENTOR. See 35 U.S.C. 102(b) and 37 CFR 1.77.
(g) BACKGROUND OF THE INVENTION: See MPEP § 608.01(c). The specification should set forth the Background of the Invention in two parts:
(1) Field of the Invention: A statement of the field of art to which the invention pertains. This statement may include a paraphrasing of the applicable U.S. patent classification definitions of the subject matter of the claimed invention. This item may also be titled “Technical Field.”
(2) Description of the Related Art including information disclosed under 37 CFR 1.97 and 37 CFR 1.98: A description of the related art known to the applicant and including, if applicable, references to specific related art and problems involved in the prior art which are solved by the applicant’s invention. This item may also be titled “Background Art.”
(h) BRIEF SUMMARY OF THE INVENTION: See MPEP § 608.01(d). A brief summary or general statement of the invention as set forth in 37 CFR 1.73. The summary is separate and distinct from the abstract and is directed toward the invention rather than the disclosure as a whole. The summary may point out the advantages of the invention or how it solves problems previously existent in the prior art (and preferably indicated in the Background of the Invention). In chemical cases it should point out in general terms the utility of the invention. If possible, the nature and gist of the invention or the inventive concept should be set forth. Objects of the invention should be treated briefly and only to the extent that they contribute to an understanding of the invention.
(i) BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S): See MPEP § 608.01(f). A reference to and brief description of the drawing(s) as set forth in 37 CFR 1.74.
(j) DETAILED DESCRIPTION OF THE INVENTION: See MPEP § 608.01(g). A description of the preferred embodiment(s) of the invention as required in 37 CFR 1.71. The description should be as short and specific as is necessary to describe the invention adequately and accurately. Where elements or groups of elements, compounds, and processes, which are conventional and generally widely known in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art, they should not be described in detail. However, where particularly complicated subject matter is involved or where the elements, compounds, or processes may not be commonly or widely known in the field, the specification should refer to another patent or readily available publication which adequately describes the subject matter.
(k) CLAIM OR CLAIMS: See 37 CFR 1.75 and MPEP § 608.01(m). The claim or claims must commence on a separate sheet or electronic page (37 CFR 1.52(b)(3)). Where a claim sets forth a plurality of elements or steps, each element or step of the claim should be separated by a line indentation. There may be plural indentations to further segregate subcombinations or related steps. See 37 CFR 1.75 and MPEP 608.01(i) - (p).
(l) ABSTRACT OF THE DISCLOSURE: See 37 CFR 1.72 (b) and MPEP § 608.01(b). The abstract is a brief narrative of the disclosure as a whole, as concise as the disclosure permits, in a single paragraph preferably not exceeding 150 words, commencing on a separate sheet following the claims. In an international application which has entered the national stage (37 CFR 1.491(b)), the applicant need not submit an abstract commencing on a separate sheet if an abstract was published with the international application under PCT Article 21. The abstract that appears on the cover page of the pamphlet published by the International Bureau (IB) of the World Intellectual Property Organization (WIPO) is the abstract that will be used by the USPTO. See MPEP § 1893.03(e).
(m) SEQUENCE LISTING: See 37 CFR 1.821 - 1.825 and MPEP §§ 2421 - 2431. The requirement for a sequence listing applies to all sequences disclosed in a given application, whether the sequences are claimed or not. See MPEP § 2422.01.
Claim Objections
Claims 2, 6, 15, 21, 22, 24, and 30 are objected to because of the following informalities:
As for claim 2, the parentheses should be removed from around the s in the phrase “optical fibre(s)”.
As for claim 6, the phrase “at least one” should be added before the phrase “the measurement interferometer” for consistency with claim 1.
As for claim 15, the amendment to the claim appears to add a semicolon to the end of line 3, after the phrase “intensity frequency bands”, but then moves straight to a period. As the US Patent Application Publication of this application does not feature any additional punctuation after that phrase and the period, the examiner recommends deleting the extra punctuation before the period.
As for claim 21, notwithstanding the rejection under 35 USC 112(b) below, the comma at the end of each parenthetical “(or modulation frequency,)” should be deleted.
As for claim 22, the phrase “at least one” should be added before the phrase “the measurement interferometer” for consistency with claim 1.
As for claim 24, the phrase “j and k each comprise an integer” should be amended to read “j and h each comprise an integer”, as there is no integer k in the equation being defined by these variables.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 16-17, 21, 22, 24, and 30 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
As for claim 16, the claim sets forth the equation fj,h = jfm1 + hfm2, where j and h are any integer. However, this equation, defining the frequencies of the interference intensity frequency bands, does not set any limits on integers j and h other than the fact that they are “any integer”. Because there is nothing in the claim preventing j and h from being the same, if j and h are both set to 0, which is an integer, then the equation becomes fj,h = 0, meaning that there is no central frequency for the interference intensity frequency bands. This renders the claim indefinite, as allowing j and h to be any integer leads to a situation where there is no central frequency for the interference intensity frequency bands.
Claim 17 is rejected by virtue of its dependence on claim 16, thereby containing all the limitations of the claim on which it depends.
For purposes of further examination below, the examiner will consider that j and h are meant to be any non-zero integer.
As for claim 21, the variable t in the equation defining the phase modulation voltage is undefined, rendering the equation indefinite.
Further regarding claim 21, the claim recites “wherein fm1 is the first frequency spacing (or modulation frequency,), fm2 is the second frequency spacing (or modulation frequency,)”. The use of parentheticals around the phrase “or modulation frequency” makes the claim unclear, as it appears the claim is reciting “or modulation frequency” as either an alternative possibility for what fm1 and fm2 can be (either the first/second frequency spacing, or the first/second modulation frequency), or merely suggested alternative language for “the first/second frequency spacing”. However, claim 1 recites that the modulated light beam comprises, in part, a first set of equally spaced frequency peaks having a first frequency spacing, with aspects of the frequency peaks in the first set being a function of a first modulation frequency (similar language exists for the second set of peaks). In other words, and as further delineated by claim 1, the first modulation frequency determines the first frequency spacing, and the second modulation frequency determines the second frequency spacing. If the modulation frequency determines the frequency spacing, how can the modulation frequency be an alternative for the frequency spacing variable in the equation used to determine the phase modulation voltage? To overcome this rejection, the examiner recommends deleting the language within the parentheticals, or explaining how the variables can be either the first/second frequency spacing or the first/second modulation frequency.
Claim 22 recites the limitation "to produce the features of said optical spectrum" in lines 9-10 of the claim. There is insufficient antecedent basis for this limitation in the claim. What “features” of the optical spectrum are being set forth here? Is it the central wavelength? The frequency spacing? The intensity? Some other aspect of the spectrum? Clarification is required.
Claim 24 recites “the apparatus of claim 1, “arranged to store a modulation scheme” in lines 1-2 of the claim. However, the claim fails to set forth the specific structure that allows the apparatus to be arranged to store a modulation scheme. Is this scheme stored in the data acquisition and analysis module of claim 1? Or is some other aspect of the apparatus used to store the claimed modulation scheme? See MPEP 2173.05(g).
Further regarding claim 24, the claim sets forth the equation fj,h = jfm1 + hfm2, where j and h each comprise an integer (while the claim says k to define the variables in the equation, the examiner interprets this as h as per the recommendation in the claim objection set forth above). However, this equation, defining the frequencies of the interference intensity frequency bands, does not set any limits on integers j and h other than the fact that they “each comprise an integer”. Because there is nothing in the claim preventing j and h from being the same, if j and h are both set to 0, which is an integer, then the equation becomes fj,h = 0, meaning that there is no central frequency for the interference intensity frequency bands. This renders the claim indefinite, as allowing j and h to be any integer leads to a situation where there is no central frequency for the interference intensity frequency bands.
For purposes of further examination below, the examiner will consider that j and h are meant to be any non-zero integer.
Additionally, claim 24 recites both “the apparatus of claim 1” and also “the method comprising” in line 15 of the claim. In addition to “the method” not having antecedent basis, setting forth both further limitations of the apparatus of claim 1 and method steps renders the claim indefinite, as one having ordinary skill in the art cannot ascertain whether or not the claim would be infringed via the apparatus limitations, or by practicing the method set forth by the claim. A single claim which claims both an apparatus and the method steps of using the apparatus is indefinite as per In re Katz Interactive Call Processing Patent Litigation, 639 F.3d 1303, 1318, 97 USPQ2d 1737, 1748-49 (Fed. Cir. 2011) and MPEP 2173.05(p).
Regarding claim 30, the claim sets forth the equation fj,h = jfm1 + hfm2, where j and h each comprise an integer (while the claim says k to define variables in the equation, the examiner interprets this as h as per the recommendation in the claim objection set forth above). However, this equation, defining the frequencies of the interference intensity frequency bands, does not set any limits on integers j and h other than the fact that they “each comprise an integer”. Because there is nothing in the claim preventing j and h from being the same, if j and h are both set to 0, which is an integer,, then the equation becomes fj,h = 0, meaning that there is no central frequency for the interference intensity frequency bands. This renders the claim indefinite, as allowing j and h to be any integer leads to a situation where there is no central frequency for the interference intensity frequency bands.
For purposes of further examination below, the examiner will consider that j and h are meant to be any non-zero integer.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-4, 6, 9, 12, 14-19, and 22 are rejected under 35 U.S.C. 103 as being unpatentable over Reasenberg et al (5,412,474) in view of Zhao et al (“Absolute distance measurement by multi-heterodyne interferometry using an electro-optic triple comb”).
Regarding claim 1, Reasenberg (Figs. 2 and 12) discloses an interferometric displacement measurement apparatus, comprising at least one measurement interferometer (elements 5-10, 12, and 27 in Fig. 12) for measuring a change in optical path difference between a measurement beam and a reference beam (the reference beam is reflected by beam splitter 6 to reference retroreflector 8; the measurement beam is transmitted through the beam splitter to reflect off of measurement retroreflector 9, with the light being recombined and detected at detector 12), the reference beam and the measurement beam having an optical path difference L1-L2 determined by a longitudinal dimension of the measurement interferometer (see Col. 6, lines 18-23), said change in optical path difference being caused by a respective displacement (see again Col. 6, lines 18-23, which states that the path length difference comes about by the movement of retroreflector 9 along the longitudinal axis of the interferometer), wherein the at least one measurement interferometer comprises a photodetector 12 for detecting the interference of the measurement beam with the reference beam (see Col. 11, lines 1-2, for example); a data acquisition and analysis module arranged to receive interference intensity data from the photodetector (these include elements like amplifier 28, mixer 29, amplifier 31, and control unit 19, with the control unit able to, among other features, output the distance measurement in Col. 12, lines 58-61); and a light source module comprising a light source 1 arranged to output light 1a having a substantially constant optical carrier frequency (see, for example, Col. 4, lines 51-54); and an electro-optic modulator 2, 2b (modulator 2, 2b may be electro-optic as per Col. 4, lines 66-68) arranged to modulate the light output from the light source; wherein the light source module is arranged to generate a modulated light beam (see Col. 4, lines 62-65), from which the measurement beam and reference beam are derived (the frequency shifted beam of light travels through fiber 4 to the interferometer); and wherein the data acquisition and analysis module is arranged to determine a measure representative of the displacement using the interference intensity data received from the photodetector (see Col. 11, lines 50-60, discussing tracking a particular minimum of transmission vs. frequency, as shown in Fig. 7A while interferometer distance L varies so as to accurately measure the change in length between the two arms of the interferometer).
Reasenberg fails to disclose that an optical spectrum of the modulated light beam comprises a first set of equally spaced frequency peaks having a first frequency spacing, wherein the number, position and power of frequency peaks in the first set are a function of a first modulation frequency and a first modulation depth, and wherein the first set is centered on a central frequency; and a second set of equally spaced frequency peaks having a second frequency spacing, wherein the number, position and power of frequency peaks in the second set are a function of a second modulation frequency and a second modulation depth, and wherein the second set is centered on the same central frequency as the first set; wherein the first frequency spacing is different to the second frequency spacing and the frequency peaks of the first and second sets are phase locked against each other; wherein the electro-optic modulator is arranged to be driven by a phase modulation voltage that causes the electro-optic modulator to generate the optical spectrum from the light source, wherein the phase modulation voltage is a time dependent function of the first modulation frequency, the second modulation frequency, the first modulation depth and the second modulation depth, the first modulation frequency determining the first frequency spacing and the second modulation frequency determining the second frequency spacing.
Zhao (Figs. 1 and 2) discloses a distance measurement interferometer using modulated light beams. The optical spectrum of the modulated light beam used for the measurement comprises a first set of equally spaced frequency peaks having a first frequency spacing (see the modes of signal comb 1 lines in Fig. 1(b), with repetition rates of 10 GHz), wherein the number, position and power of frequency peaks in the first set are a function of a first modulation frequency and a first modulation depth (the number, position, and power of the peaks are a function of a first modulation frequency imparted by phase modulators PM1 and PM2 and modulation depth imparted by IM1), and wherein the first set is centered on a central frequency (1500 nm which is the central wavelength of the seed source as per Col. 1 of page 808; see also the central frequency line in Fig. 1(b)); and a second set of equally spaced frequency peaks having a second frequency spacing (see the modes of signal comb 2 lines in Fig. 1(b), with repetition rates of 10.001 GHz), wherein the number, position and power of frequency peaks in the second set are a function of a second modulation frequency and a second modulation depth (the number, position, and power of the peaks are a function of a second modulation frequency imparted by phase modulators PM3 and PM4 and a modulation depth imparted by IM2), and wherein the second set is centered on the same central frequency as the first set (1500 nm which is the central wavelength of the seed source as per Col. 1 of page 808; see also the central frequency line in Fig. 1(b)); wherein the first frequency spacing is different to the second frequency spacing (the repetition rate for signal comb 1 is 10 GHz and for signal comb 2 is 10.001 GHz as seen in Fig. 1(b) and in Col. 1 of page 808), and the frequency peaks of the first and second sets are phase locked against each other (the three sets of combs are locked to each other using a PDH locking technique as found in Col. 1 of page 808); wherein the electro-optic modulator is arranged to be driven by a phase modulation voltage that causes the electro-optic modulator to generate the optical spectrum from the light source (the modulators are driven using signals from MWS1 and MWS2 via a Rb clock; see Fig. 1(a) and Col. 1 of page 808), wherein the phase modulation voltage is a time dependent function of the first modulation frequency, the second modulation frequency, the first modulation depth and the second modulation depth (this is an inherent feature of any voltage applied to an electro-optic modulator for modulating light), the first modulation frequency determining the first frequency spacing and the second modulation frequency determining the second frequency spacing (see Fig. 1(b) and Col. 1 of page 808 showing and discussing how the frequency spacing is determined).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to substitute the optical spectrum of the modulated light beam used by Reasenberg for the modulated optical spectrum used by Zhao for interferometric measurements, the motivation being that the frequency modulation and combs used by Zhao allow for performing measurements having a high non-ambiguous range (NAR) and high resolution simultaneously, along with a high update rate and low cost (see the last full paragraph of Col. 2 on page 810).
As for claim 2, Reasenberg discloses connecting the light source to the measurement interferometer via fiber 4 (see Fig. 12).
As for claim 3, Reasenberg discloses that the measure representative of the displacement is the change in optical path difference between the reference and measurement beams (see Col. 11, lines 50-60, discussing tracking a particular minimum of transmission vs. frequency, as shown in Fig. 7A while interferometer distance L varies so as to accurately measure the change in length between the two arms of the interferometer).
As for claim 4, Reasenberg discloses that the at least one measurement interferometer has a distal end and a proximal end (where fiber 4 enters the interferometer with the light from the light source) with a reflector 9 defining the distal end, wherein the measure representative of the displacement is the displacement of said reflector (see Col. 6, lines 18-21, discussing the movement of the retroreflector changing the path length difference in the interferometer).
As for claim 6, Reasenberg discloses that the at least one measurement interferometer comprises a beam splitter 6 comprising a beam splitting surface arranged to split the modulated beam into the measurement and reference beams (see, for example, Col. 5, line 66 – Col. 6, line 2).
As for claim 9, Reasenberg discloses that the at least one measurement interferometer comprises a respective optical fiber 4, a respective beam splitter 6, and a respective reflector 9.
As for claim 12, Reasenberg discloses that the light source is arranged to output light centered on the central frequency which is known in absolute terms with an uncertainty less than the desired displacement measurement uncertainty (see Col. 4, lines 51-53, which states that the laser provides a beam of optical waves of a single frequency, which would be known to one having ordinary skill in the art from selecting the laser used in the interferometer; see also Col. 11, lines 50-60, disclosing that the optical carrier frequency is tracked while the interferometer distance L varies).
As for claim 15, Reasenberg inherently discloses that the interference intensity data comprises a plurality of odd interference intensity bands and a plurality of even interference intensity bands, as odd interference would be areas of destructive interference within the interference pattern while even interference would be areas of constructive interference within the interference pattern.
As for claim 16, while the combination of Reasenberg and Zhao discloses frequencies on which the emitted light beam are centered (Reasenberg discloses this as the single wavelength of the laser in Col. 4, lines 51-53 and Zhao discloses this as 1500 nm which is the central wavelength of the seed source as per Col. 1 of page 808; see also the central frequency line in Fig. 1(b)), and Zhao discloses as set forth above in claim 1 the specific modulation frequencies used (see Fig. 1(a)), the combination fails to disclose that the plurality of odd and even interference intensity frequency bands are centered on the frequencies set forth in the equation.
However, it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980), and it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the plurality of odd and even interference intensity frequency bands be centered on the frequencies set forth the claimed equation, the motivation being that there are a finite number of frequencies appropriate for interferometric displacement measurements, and one having ordinary skill in the art would be motivated to experiment with different frequencies until one that gives the most accurate results is found. Additionally, one having ordinary skill in the art would recognize that interference intensity frequency bands must be odd if j+h is equal to an odd number, and even if j+h is equal to an even number.
As for claim 17, all odd combinations of j and h will inherently give frequencies fj,h that are different from all even combinations of j and h due to the nature of the claimed equation in claim 16.
As for claim 18, Reasenberg discloses that the data acquisition and analysis module includes a low pass filter having a pass band adjusted to suit a required maximum motion speed (see amplifier 28, which acts as a filter that may pass only a frequency band around the modulation frequency, this would be a pass band adjusted to suit a required maximum motion speed of the displacement of reflector 9; see Col. 14, lines 9-11).
As for claim 19, Zhao further discloses that the first and second frequency spacings are substantially constant in time (the spacings are locked to a rubidium clock as per Col. 1 of page 808, making them be constant in time).
As for claim 22, the combination of Reasenberg and Zhao discloses the claimed invention as set forth above regarding claim 1, but fails to disclose the specific values of the modulation frequencies set forth in the claim.
However, it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980), and it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to select a maximum value for the larger of the two modulation frequencies to be half of a Nyquist frequency of the data acquisition and analysis module, where the larger of the first and second modulation frequencies is selected to be at least 5% lower than the maximum value or is elected to be lower than the maximum value by at least half the maximum expected Doppler shift caused by motion within the at least one measurement interferometer, with the smaller of the first and second modulation frequencies being selected to produce features of the optical spectrum, the motivation being that there are a finite number of frequencies appropriate for interferometric displacement measurements, and one having ordinary skill in the art would be motivated to experiment with different frequencies until one that gives the most accurate results is found.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Reasenberg et al (5,412,474) in view of Zhao et al (“Absolute distance measurement by multi-heterodyne interferometry using an electro-optic triple comb”) and in further view of Warden et al (2013/0148129).
As for claim 10, the combination of Reasenberg and Zhao discloses the claimed invention as set forth above regarding claim 1, but fails to disclose a plurality of measurement interferometers having respectively different longitudinal dimensions, wherein the light source module and data acquisition module are common to the plurality of measurement interferometers.
Warden, in an apparatus for measuring distance (Fig. 4), discloses the use of a plurality of interferometers 15, 15’ (even if interferometer 15’ is termed a reference interferometer by the Warden abstract, it still performs a distance measurement, making it a measurement interferometer) having respectively different longitudinal dimensions (see Fig. 4; the longitudinal dimension of interferometer 15’ is different than the dimension of interferometer 15; for more specifics, see Fig. 2 and the difference between Dref and Dmeas), wherein the light source module 120 and the data acquisition and analysis module 251, 252 are the same for both interferometers (see Fig. 4).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have a plurality of measurement interferometers using a common light source and analysis module in the device of Reasenberg and Zhao, with the interferometers having different longitudinal dimensions, as taught by Warden, the motivation being that using multiple interferometers minimizes or tracks any errors that may result from the change of the length of an arm during interferometric measurement (see paragraph 0035), while using the same light source and analysis module for multiple interferometers reduces the number of elements needed for measurements and allows for the same light to be used in all the interferometers, simplifying operation and reducing costs.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Reasenberg et al (5,412,474) in view of Zhao et al (“Absolute distance measurement by multi-heterodyne interferometry using an electro-optic triple comb”) and in further view of Gu et al (2016/0356823).
As for claim 21, the combination of Reasenberg and Zhao discloses the claimed invention as set forth above regarding claim 1, but fails to disclose that the phase modulation voltage is proportional to β1sin(2πfm1t) + β2sin(2πfm2t), wherein fm1 is the first frequency spacing and fm2 is the second frequency spacing, β1 is the first modulation depth and β2 is the second modulation depth.
Gu, in an interferometric sensor, discloses that phase modulator 30, shown in Fig. 3, would apply a sinusoidal modulation of β(t)=βsin(Ωt), with Ω being the modulation frequency (see paragraph 0053).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the phase modulation voltage in the combination of Reasenberg and Zhao be proportional to β1sin(2πfm1t) + β2sin(2πfm2t) as suggested by Gu, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). It follows that, in a case where there are multiple phase modulators, such as in Reasenberg and Zhao, that the first phase modulator would apply a sinusoidal modulation of β1sin(2πfm1t), and the second phase modulator would apply a sinusoidal modulation of β2sin(2πfm2t), given the suggestion of the sinusoidal phase modulation disclosed in paragraph 0053 of Gu for use in interferometric measurements.
Allowable Subject Matter
Claims 20 and 28 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 24 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
Claim 30 would be allowable if rewritten or amended to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action.
The following is a statement of reasons for the indication of allowable subject matter:
As to claim 20, the prior art of record, taken either alone or in combination, fails to disclose or render obvious the further limitation of claim 1, wherein the first frequency spacing (Δv1) and the second frequency spacing (Δv2) are such that k
∆
v
1
∆
v
2
≠
n
for k>
10
6
, where k and n are integers, in combination with the rest of the limitations of the above claim.
Further regarding claim 20, the instant specification, on page 12, lines 20-25, defines the ratio set forth in this claim as a “near-irrational” ratio, which is used in the instant context to describe an irreducible fraction. The prior art of record does not disclose or suggest as obvious such a ratio to describe the frequency spacing as claimed in claim 20.
For claim 24, the examiner assumes that the “method” set forth by the claim is function for determining a modulation scheme that is used for interferometric displacement measurement (similarly to claim 30), with that function being performed by the data acquisition and analysis module set forth by claim 1.
As to claim 24, the prior art of record, taken either alone or in combination, fails to disclose or render obvious the further limitation of claim 1, wherein the modulation scheme is determined by determining a modulation frequency pair comprising the first modulation frequency and the second modulation frequency; given said modulation frequency pair, determining a modulation depth pair comprising the first modulation depth and the second modulation depth, by: for each of a plurality of modulation depth pairs, wherein the modulation depth of the first modulation depth is between 0 and 6 and the modulation depth of the second modulation depth is between 0 and 6:for each of a plurality of optical path differences: evaluating the plurality of modulation depth pairs; determining a first measure representative of the sum of the power of the odd interference intensity frequency bands and a second measure representative of the sum of the power of the even interference intensity frequency bands; for each of the plurality of modulation depth pairs: determining the lowest first measure representative of the sum of the power of the odd interference intensity frequency bands and the lowest second measure representative of the sum of the power of the even interference intensity frequency bands from the plurality of optical path differences; and taking the lower of the lowest first measure representative of the sum of the power of the odd interference intensity frequency bands and the lowest second measure representative of the sum of the power of the even interference intensity frequency bands, and selecting one of the plurality of modulation depth pairs, wherein the selected modulation depth pair gives the largest value of said lower measure, in combination with the rest of the limitations of the above claim.
As to claim 28, the prior art of record, taken either alone or in combination, fails to disclose or render obvious the further limitation of claim 1, wherein the data acquisition and analysis module is arranged to carry out an analysis algorithm for determining a change in optical path difference from a time-varying interference intensity signal, the analysis algorithm comprising: receiving a time-varying interference intensity signal, derived from interference detected at a photodetector, comprising a plurality of odd interference intensity frequency bands and a plurality of even interference intensity frequency bands; extracting each odd interference intensity frequency band using a respective lock-in amplifier; summing and normalizing the plurality of odd interference intensity frequency bands; extracting each even interference intensity frequency band using a respective lock-in amplifier; summing and normalizing the plurality of even interference intensity frequency bands output from the lock-in amplifiers; generating an interferometric quadrature signal by combining the normalized sum of the odd interference intensity frequency bands and the normalized sum of the even interference intensity frequency bands; and calculating the change in optical path difference from said interferometric quadrature signal, in combination with the rest of the limitations of the above claim.
As to claim 30, the prior art of record, taken either alone or in combination, fails to disclose or render obvious a method of determining a modulation scheme for use in an interferometric measurement displacement apparatus, the method comprising determining a modulation frequency pair comprising the first modulation frequency and the second modulation frequency; given said modulation frequency pair, determining a modulation depth pair comprising the first modulation depth and the second modulation depth, by: for each of a plurality of modulation depth pairs, wherein the modulation depth of the first modulation depth is between 0 and 6 and the modulation depth of the second modulation depth is between 0 and 6: for each of a plurality of optical path differences: evaluating the plurality of modulation depth pairs; determining a first measure representative of the sum of the power of the odd interference intensity frequency bands and a second measure representative of the sum of the power of the even interference intensity frequency bands; for each of the plurality of modulation depth pairs: determining the lowest first measure representative of the sum of the power of the odd interference intensity frequency bands and the lowest second measure representative of the sum of the power of the even interference intensity frequency bands from the plurality of optical path differences; and taking the lower of the lowest first measure representative of the sum of the power of the odd interference intensity frequency bands and the lowest second measure representative of the sum of the power of the even interference intensity frequency bands, and selecting one of the plurality of modulation depth pairs, wherein the selected modulation depth pair gives the largest value of said lower measure, in combination with the rest of the limitations of the above claim.
Further regarding claims 24 and 30 above, while the prior art cited above discloses modulation schemes for adjusting the optical spectrum of an input light beam for use in an interferometric displacement measurement apparatus, none of that prior art discloses determining the modulation scheme to the extent by which it is disclosed in those claims.
Further regarding claim 28 above, while Reasenberg discloses “Frequency counter 15, which measures the frequency variation required to maintain the null condition, can measure frequencies to the microwave band with high accuracy, and so is a direct and extremely accurate measure of the change in length between the two arms of the interferometer” (see Col. 11, lines 55-60) for the determination of the change in optical path difference, Reasenberg, along with the rest of the prior art of record, fails to disclose or suggest the detailed algorithm as set forth by claim 28.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. WO 2023/002050 to Van De Sande discloses an interferometer 202 for measuring a position of a target 211 as it moves relative to a reference reflector 207 (see Fig. 2 and paragraph 0059). Van De Sande further discloses, “The benefit of such a system, for instance comprising a single laser source (e.g. modulated line locked laser source) as the common light source, is suitable for performing a number of independent position measurements each with approximately the same (optimized) modulation depth” (see paragraph 0028) and “Furthermore, since the modulation depth is proportional to the path length difference between the interfered beams the variation in modulation depth between independent sensing units or devices can also be minimized. With this setup one laser source (e.g. a modulated line locked laser source) can be used to provide the input for a number of independent position measurements, each with approximately the same optimal modulation depth. This is for instance ideally suitable for a system comprising sensing units for measuring a relative position along multiple axes” (see paragraph 0069), but fails to disclose the specific limitations indicated as allowable as set forth above.
Additionally, “Synthetic wavelength interferometry of an optical frequency comb for absolute distance measurement” by Wu et al discloses an additional optical frequency comb interferometer that performs distance measurement (see Fig. 1).
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/Michael A Lyons/Primary Examiner, Art Unit 2877 December 3, 2025