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 .
Claim Interpretation
MPEP § 2111.01 stated that “… Under a broadest reasonable interpretation (BRI), words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the relevant time. The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification - the greatest clarity is obtained when the specification serves as a glossary for the claim terms …”. Thus under a broadest reasonable interpretation, the greatest clarity is obtained when the specification (e.g., see “… In preferred examples, the maximum transmittance of the bandpass filter is at least 65% …” in the last paragraph on pg. 5) serves as a glossary for the claim term “maximum transmittance”.
The specification (e.g., see “… For example, the peak wavelength may preferably be approximately 3250 nm or in the range of 3225 and 3260 nm …” in the first complete paragraph on pg. 6) serves as a glossary for the claim term “peak wavelength”.
The specification (e.g., see “… Preferably the FWHM of the bandpass filter is in the range of 80 nm to 200 nm, or more preferably 80 nm to 120 nm …” in the third paragraph on pg. 6) serves as a glossary for the claim term “full width at half maximum, FWHM”.
The specification (e.g., see “… Preferably, the upper cut-off wavelength of the bandpass filter is in the range of 3275 nm to 3325 nm …” in the fourth paragraph on pg. 6) serves as a glossary for the claim term “an upper cut-off wavelength”.
The specification (e.g., see “… Preferably, the band pass filter has a lower cut-off wavelength in the range from 3100nm to 3200nm, …” in the fifth paragraph on pg. 6) serves as a glossary for the claim term “a lower cut-off wavelength”.
The specification (e.g., see “… Preferably the upper slope of the transmission spectrum of the bandpass filter has an average gradient in the range of 0.5% to 1.5% … Preferably the lower slope of the transmission spectrum of the bandpass filter has an average gradient in the range from 0.5% to 1.5% …” in the third and fourth paragraphs on pg. 7) serves as a glossary for the claim term “an average gradient”.
The specification (e.g., see “… output signal produced by the first infrared detector is preferably dependent on the intensity of the radiation incident on the first infrared detector. However, in further examples, the signal may be dependent on other properties of the radiation received by the first infrared detector (e.g. spectral intensity, irradiance, spectral irradiance or other spectral properties of the incident radiation) …” in the first complete paragraph on pg. 8) serves as a glossary for the claim term “an electromagnetic spectra of the output signal”.
The specification (e.g., see “… located relatively close to or adjacent to one another, whilst radiation must take a relatively long route between the two components via a mirror. In some examples the LED and the infrared detector may be mounted on a single circuit board …” in the first complete on pg. 9) serves as a glossary for the claim term “adjacent close to”.
The specification (e.g., see “… Preferably the length of the first optical path is at least twice the length of the second optical path …” in the first paragraph on pg. 11) serves as a glossary for the claim term “length of the first optical path”.
The specification (e.g., see “… apertures 11a through which a gas sample may enter or be introduced into the sample chamber 11 …” in the first paragraph on pg. 20) serves as a glossary for the claim term “a sample chamber for containing the gas sample”.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim(s) 21-24 is/are rejected under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for pre-AIA the inventor(s), at the time the application was filed, had possession of the claimed invention.
While the specification discloses to calculate a first estimate of the proportion of radiation emitted by the light emitting diode along the first optical path absorbed by the contents of the sample chamber based on the calculated ratio between the output signal and the short path reference signal and to calculate a second estimate of the proportion of radiation emitted by the light emitting diode along the first optical path absorbed by the contents of the sample chamber based on the calculated ratio between the output signal and the internal reference signal (e.g., see “… first normalised intensity Inorm1 is a ratio of the output signal I0 to the short path reference signal lSP … second normalised intensity Inarmz is calculated from a ratio of the output signal I0 to the internal reference signal IINT …” on pg. 37), there does not appear to be any disclosure of to calculate a first estimate of the proportion of radiation emitted by the light emitting diode along the first optical path absorbed by the contents of the sample chamber based on the calculated ratio between the output signal and the short path reference signal and to calculate a second estimate of the proportion of radiation emitted by the light emitting diode along the first optical path absorbed by the contents of the sample chamber based on the calculated ratio between the output signal and the short path reference signal. Therefore, there does not appear to be a written description of the newly added claim limitation “to calculate a first estimate of the proportion of radiation emitted by the light emitting diode along the first optical path absorbed by the contents of the sample chamber based on the calculated ratio between the output signal and the short path reference signal and to calculate a second estimate of the proportion of radiation emitted by the light emitting diode along the first optical path absorbed by the contents of the sample chamber based on the calculated ratio between the output signal and the short path reference signal” in the application as filed.
Claim(s) dependent on the claim(s) discussed above also fail(s) to comply with the written description requirement for the same reasons.
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 pre-AIA 35 U.S.C. 112, 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.
Claim(s) 18 is/are rejected under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, 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 pre-AIA the applicant regards as the invention.
Claim(s) 18 is/are directly or indirectly dependent on a canceled base claim. Therefore, the claim is incomplete and fails to particularly point out and distinctly claim the subject matter which applicant regards as the invention (MPEP § 608.01(n)).
Claim(s) dependent on the claim(s) discussed above is/are also indefinite for the same reasons.
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 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.
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 at the time any inventions covered therein were effectively filed 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 at the time a later invention was effectively filed 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.
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 of this title, 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.
Claim(s) 1, 3-6, 8, 9, 15, 16, and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Isshiki et al. (US 2022/0307976) in view of Iutzi (US 2024/0405148) and Tkachuk (US 2009/0268204).
In regard to claim 1, Isshiki et al. disclose a system for detecting a concentration of methane in a gas sample comprising a gas sensor and a processor, the gas sensor comprising:
(a) a sample chamber for containing the gas sample (e.g., see “… first light guide part 21 …” in Fig. 1,
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, and paragraph 30);
(b) a light emitting diode arranged to emit infrared radiation into the sample chamber (e.g., see “… first light source 31 is preferably an incoherent light source, and is, for example, a Light Emitting Diode (LED) … When the second light source 32 is integrated into the first light source 31, the first light guide part 21 and the second light guide part 22 should be configured so that the infrared light emitted from the light source is taken to each light guide part …” in Fig. 1, Fig. 2, and paragraphs 32 and 36);
(c) a first infrared detector configured to output an output signal based on the radiation it receives (e.g., see “… first light receiving part 51 generates a first detection signal according to the first intensity of the light received and outputs the signal …” in Fig. 1, Fig. 2, and paragraph 50);
(d) a bandpass filter configured to filter radiation passing therethrough (e.g., see “… gas to be measured is methane … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in Fig. 1, Fig. 2, and paragraphs 42 and 43),
wherein the light emitting diode, the bandpass filter and the first infrared detector are arranged such that at least a portion of the radiation emitted from the light emitting diode is transmitted through the bandpass filter and along a first optical path through the sample chamber before being received by the first infrared detector (e.g., see “… first optical path L1 …” in Fig. 1, Fig. 2, and paragraph 51),
wherein the bandpass filter has a full width at half maximum, FWHM, in the range from 70 nm to 300 nm and an upper cut-off wavelength of less than or equal to 3350 nm (e.g., “… "transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter … first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in paragraphs 23, 39, 42, and 43 and a prima facie case of obviousness exists (MPEP § 2144.05) since the claimed 70-300 nm FWHM range overlap the “full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less” range disclosed by the cited prior art and the claimed ≤3350 nm upper cut-off wavelength range overlap the “"transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter ” within “first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less” range disclosed by the cited prior art),
wherein the upper cut-off wavelength is the wavelength at which the bandpass filter has a transmittance of 5% of the maximum transmittance of the bandpass filter, the upper cut-off wavelength being greater than a peak wavelength of the bandpass filter at which maximum transmittance occurs (e.g., ““… "transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in paragraphs 23 and 43), and
wherein the FWHM is a difference between the wavelengths at which the transmittance of the bandpass filter is at 50% of the maximum transmittance of the bandpass filter (e.g., “… full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in paragraph 43); and
(e) a second infrared detector configured to output a short path reference signal based on the radiation it receives, wherein the light emitting diode and the second infrared detector are arranged such that a portion of the radiation emitted from the light emitting diode is transmitted along a second optical path through the sample chamber before being received by the second infrared detector, and wherein a length of the first optical path through the sample chamber is at least twice a length of the second optical path through the sample chamber, (e.g., see “… operation part 60 may include at least one of the drive part 70, a general-purpose processor that executes a function according to a program to be read, and a dedicated processor specialized for a specific process … based on the first detection signal output from the first light receiving part 51 … based on the second detection signal output from the second light receiving part 52 … first optical path length l1 is equal to or longer than the second optical path length l2 … first light source 31, the second light source 32, the first light receiving part 51 and the second light receiving part 52 may preferably be mounted on the same substrate …” in Fig. 1, Fig. 2, and paragraphs 85-87, 104, and 113 and a prima facie case of obviousness exists (MPEP § 2144.05) since the claimed at least twice range overlap the “longer than” range disclosed by the cited prior art),
wherein the processor (e.g., see “… operation part 60 may include at least one of the drive part 70, a general-purpose processor that executes a function according to a program to be read, and a dedicated processor specialized for a specific process …” in Fig. 1 and paragraph 85) configured to:
receive the output signal from the first infrared detector (e.g., see “… based on the first detection signal output from the first light receiving part 51 …” in Fig. 1 and paragraph 86), the short path reference signal from the second infrared detector (e.g., see “… based on the second detection signal output from the second light receiving part 52 … first optical path length l1 is equal to or longer than the second optical path length l2 …” in Fig. 1 and paragraphs 87 and 104);
compare the output signal with the short path reference signal (e.g., “… For example, the operation part 60 calculates the concentration of gas to be measured by subtracting the second attenuation amount from the amount obtained by multiplying the first attenuation amount by a proportional constant …” in paragraph 88); and
determine the concentration of methane in the sample chamber based on the comparison of the output signal and the short path reference signal (e.g., “… non-dispersive infrared (NDIR) type device configured to measure the concentration of a gas … methane … equation (1) according to the Lambert-Beer law.
∆
I
=
I
0
1
-
e
-
e
c
l
(1), where I0 is the intensity of infrared light in the absence of gas in the optical path, e is a gas-specific absorption coefficient, c is concentration of gas, and l is an optical path length in a range where gas is present. From equation (1), it is clear that the attenuation amount ΔI of the intensity of infrared light by gas behaves exponentially … attenuation amount of the first intensity of infrared light by interference gas present in the first optical path L and the attenuation amount of the second intensity of infrared light by interference gas present in the second optical path L2 are in a proportionate relationship. Therefore, first, the operation part 60 subtracts the second attenuation amount from the amount obtained by multiplying the first attenuation amount by a proportional constant, and removes the attenuation amount of the first intensity of infrared light by interference gas present in the first optical path L1 and the attenuation amount of the second intensity of infrared light by interference gas present in the second optical path L2 to perform the interference removal operation in which the effect of infrared light by interference gas is removed … operation part 60 calculates the concentration of the gas to be measured by applying the concentration calculation table or the fitting of exponential function to the output after the interference removal operation in which the effect of infrared light absorption by interference gas is removed. It is preferable that the operation part 60 calculates the concentration of gas to be measured by using a polynomial of third order or higher in the equation (2) …” in paragraphs 26, 27, 90, 91, 122, 123, and 128).
The system of Isshiki et al. lacks a third infrared detector configured to output an internal reference signal based on the radiation it receives, wherein the light emitting diode and the third infrared detector are arranged such that a portion of the radiation emitted from the light emitting diode is received by the third infrared detector without being transmitted through the sample chamber and without being transmitted through the gas to be tested, wherein the processor receive the internal reference signal from the third infrared detector and compare the output signal with the internal reference signal, and the processor to output an indication of the concentration of methane in the sample chamber. However, “… NDIR …” is known to one of ordinary skill in the art (e.g., see (e.g., “… One of the most popular techniques for quantitative measurement of the industrially significant gases such as CO2, NOx, water vapor, methane etc. is carried out by optical absorption. Most of these gases have strong vibrational absorption spectra in the 1-12 µm region … nondispersive IR measurements (NDIR) … measurements are taken: color-1 incident on main detector, color-1 incident on reference detector … color-2 incident on reference 2 … goal of this system with four separate measurements is to compensate out these factors, and obtain a figure that is dependent only on gas concentration … define the ratio r1 as the ratio of main/reference detector signal for color-1 … a full-ratio, rf, can be defined as the ratio of r1 to r2 … rf can be used as a sensor output that, for a well-designed system, remains near 1 and for an ideal system, remains precisely 1 … In the presence of gas at concentration c, however, this full-ratio changes, via the transmission term … transmission as a function of concentration is described by Beer-Lambert Law … ASICs are used to process the detector signals while processing any necessary ratios … performance of processes or methods may utilize program instructions executable by a device (e.g., a computer, a processor, or other device) to perform, or control performance of, the processes or methods … a user interface include printers or display screens for visual presentation of output …” in paragraphs 97, 104, 196, 198, 199, 200, 202, 203, 240, 287, and 297 of Iutzi and “… non-dispersive infrared (NDIR) measurement have been recognized for many years as sensitive, stable and reliable methods of gas concentration measurement … in the detection of methane, the waveband of emitted radiation will be around 3.2 to 3.5 microns … first optical path A is approximately 3-4 times the length of the second optical path B. The relatively short length of the second optical path means that there is little interaction with the sample contained in the chamber 6 and, consequently, minimal absorption of radiation … optical fibre is arranged to receive a portion of the radiation emitted by source 3 and direct it, through the chamber 6, to detector 2. The optical fibre 9 constitutes optical path B. The remaining radiation which is not incident on fibre 9 passes on optical path A to detector 1. Since the whole of path B is contained within optical fibre 9, as in the FIG. 4a embodiment, there is no absorption on the reference channel …” in paragraphs 3, 55, 56, and 79 of Tkachuk). Therefore it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to provide a fiber coupled third infrared detector in the system of Isshiki et al. for obtaining an internal reference signal that is use by the processor to output a methane concentration based an output signal comparison, in order to achieve “no absorption on the reference channel” (as an improvement over “relatively short length of the second optical path means that there is little interaction with the sample contained in the chamber 6 and, consequently, minimal absorption of radiation”).
In regard to claim 3 which is dependent on claim 1, Isshiki et al. also disclose that the peak wavelength, at which maximum transmittance of the bandpass filter occurs, is in the range from 3200 nm to 3260 nm (e.g., “… "transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter … first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in paragraphs 23, 39, 42, and 43 and a prima facie case of obviousness exists (MPEP § 2144.05) since the claimed 3200-3360 nm peak wavelength range overlap the “"transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter ” within “first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less” range disclosed by the cited prior art).
In regard to claim 4 which is dependent on claim 1, Isshiki et al. also disclose that the FWHM of the bandpass filter is in the range of 80 nm to 200 nm (e.g., “… "transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter … first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in paragraphs 23, 39, 42, and 43 and a prima facie case of obviousness exists (MPEP § 2144.05) since the claimed 80-200 nm FWHM range overlap the “full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less” range disclosed by the cited prior art).
In regard to claim 5 which is dependent on claim 1, Isshiki et al. also disclose that the upper cut-off wavelength of the bandpass filter is in the range of 3275 nm to 3325 nm (e.g., “… "transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter … first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in paragraphs 23, 39, 42, and 43 and a prima facie case of obviousness exists (MPEP § 2144.05) since the claimed 3275-3325 nm upper cut-off wavelength range overlap the “"transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter ” within “first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less” range disclosed by the cited prior art).
In regard to claim 6 which is dependent on claim 1, Isshiki et al. also disclose that the bandpass filter has a lower cutoff wavelength in the range from 3100nm to 3200nm, wherein the lower cut-off wavelength is the wavelength at which the bandpass filter has a transmittance of 5% of the maximum transmittance of the bandpass filter, the lower cut-off wavelength being smaller than the peak wavelength of the bandpass filter at which maximum transmittance occurs (e.g., “… "transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter … first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in paragraphs 23, 39, 42, and 43 and a prima facie case of obviousness exists (MPEP § 2144.05) since the claimed 3100-3200 nm lower cut-off wavelength range overlap the “"transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter ” within “first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less” range disclosed by the cited prior art).
In regard to claims 8 and 9 which are dependent on claim 1, Isshiki et al. also disclose a first mirror positioned along the first optical path and configured to reflect radiation from the light emitting diode to the first infrared detector, wherein the first mirror is flat, concave, parabolic or spherical (e.g., see “… first optical path L1 … first light guide part 21 reflects infrared light multiple times or rotationally converts the radiation angle at the time of emitting infrared light so that infrared light emitted from the first light source 31 eventually reaches the first light receiving part 51. The first light guide part 21 includes a mirror 211 and a mirror 212 …” in Fig. 1, Fig. 2, and paragraphs 51, 73, and 74).
In regard to claim 15 which is dependent on claim 1, the system of Isshiki et al. lacks that the light emitting diode and the third infrared detector are arranged such that the radiation received by the third infrared detector from the light emitting diode is transmitted along a third optical path, and wherein the third optical path shorter than the first and second optical paths. However, “… NDIR …” is known to one of ordinary skill in the art (e.g., see (e.g., “… One of the most popular techniques for quantitative measurement of the industrially significant gases such as CO2, NOx, water vapor, methane etc. is carried out by optical absorption. Most of these gases have strong vibrational absorption spectra in the 1-12 µm region … nondispersive IR measurements (NDIR) … measurements are taken: color-1 incident on main detector, color-1 incident on reference detector … color-2 incident on reference 2 … goal of this system with four separate measurements is to compensate out these factors, and obtain a figure that is dependent only on gas concentration … define the ratio r1 as the ratio of main/reference detector signal for color-1 … a full-ratio, rf, can be defined as the ratio of r1 to r2 … rf can be used as a sensor output that, for a well-designed system, remains near 1 and for an ideal system, remains precisely 1 … In the presence of gas at concentration c, however, this full-ratio changes, via the transmission term … transmission as a function of concentration is described by Beer-Lambert Law … ASICs are used to process the detector signals while processing any necessary ratios … performance of processes or methods may utilize program instructions executable by a device (e.g., a computer, a processor, or other device) to perform, or control performance of, the processes or methods … a user interface include printers or display screens for visual presentation of output …” in paragraphs 97, 104, 196, 198, 199, 200, 202, 203, 240, 287, and 297 of Iutzi and “… non-dispersive infrared (NDIR) measurement have been recognized for many years as sensitive, stable and reliable methods of gas concentration measurement … in the detection of methane, the waveband of emitted radiation will be around 3.2 to 3.5 microns … first optical path A is approximately 3-4 times the length of the second optical path B. The relatively short length of the second optical path means that there is little interaction with the sample contained in the chamber 6 and, consequently, minimal absorption of radiation … optical fibre is arranged to receive a portion of the radiation emitted by source 3 and direct it, through the chamber 6, to detector 2. The optical fibre 9 constitutes optical path B. The remaining radiation which is not incident on fibre 9 passes on optical path A to detector 1. Since the whole of path B is contained within optical fibre 9, as in the FIG. 4a embodiment, there is no absorption on the reference channel …” in paragraphs 3, 55, 56, and 79 of Tkachuk). Therefore it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to provide a fiber coupled third infrared detector in the system of Isshiki et al. for a third optical path shorter than the first and second optical paths, in order to achieve “minimal absorption of radiation” with the goal of “no absorption on the reference channel”.
In regard to claim 16 which is dependent on claim 1, the system of Isshiki et al. lacks an internal chamber disposed between the light emitting diode and the third infrared detector, wherein the internal chamber is separate from the sample chamber, and wherein the gas sensor is arranged such that the portion of radiation received from the light emitting diode by the third infrared detector is transmitted along a third optical path extending through the internal chamber, an wherein the internal chamber contains a vacuum or partial vacuum, or is filled with a gas or gas mixture that is substantial transmissive to infrared radiation in the range of 3100 to 3400 nm. However, “… NDIR …” details are known to one of ordinary skill in the art (e.g., see “… main components of a nondispersive infrared sensor (NDIR) sensor are an infrared source (lamp), a sample chamber or light tube, a light filter and an infrared detector. The IR light is directed through the sample chamber towards the detector. In parallel there is another chamber with an enclosed reference gas, typically nitrogen. The gas in the sample chamber causes absorption of specific wavelengths according to the Beer-Lambert law, and the attenuation of these wavelengths is measured by the detector to determine the gas concentration …” in paragraph 5 of Iutzi). Therefore it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to provide “another chamber with an enclosed reference gas” in the system of Isshiki et al., in order to “to determine the gas concentration”.
In regard to claim 19, Isshiki et al. disclose a method for detecting a concentration of methane in a gas sample, comprising:
(a) providing a gas sensor comprising:
(a1) a light emitting diode arranged to emit infrared radiation into a sample chamber configured for containing the gas sample (e.g., see ““… first light guide part 21 … first light source 31 is preferably an incoherent light source, and is, for example, a Light Emitting Diode (LED) … When the second light source 32 is integrated into the first light source 31, the first light guide part 21 and the second light guide part 22 should be configured so that the infrared light emitted from the light source is taken to each light guide part …” in Fig. 1, Fig. 2, and paragraphs 30, 32, and 36);
(a2) a first infrared detector configured to output an output signal based on the radiation it receives (e.g., see “… first light receiving part 51 generates a first detection signal according to the first intensity of the light received and outputs the signal …” in Fig. 1, Fig. 2, and paragraph 50); and
(a3) a bandpass filter configured to filter radiation passing therethrough (e.g., see “… gas to be measured is methane … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in Fig. 1, Fig. 2, and paragraphs 42 and 43),
wherein the light emitting diode, the bandpass filter and the first infrared detector are arranged such that at least a portion of the radiation emitted from the light emitting diode is transmitted through the bandpass filter and along a first optical path through the sample chamber before being received by the first infrared detector (e.g., see “… first optical path L1 …” in Fig. 1, Fig. 2, and paragraph 51),
wherein the bandpass filter has a full width at half maximum, FWHM, in the range from 70 nm to 300 nm and an upper cut-off wavelength of less than or equal to 3350 nm (e.g., “… "transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter … first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in paragraphs 23, 39, 42, and 43 and a prima facie case of obviousness exists (MPEP § 2144.05) since the claimed 70-300 nm FWHM range overlap the “full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less” range disclosed by the cited prior art and the claimed ≤3350 nm upper cut-off wavelength range overlap the “"transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter ” within “first optical filter 41 transmits the light in the first transmission band … central wavelength of the first transmission band in the first optical filter 41 is preferably the wavelength of 3.2 µm or more and 3.4 µm or less … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less” range disclosed by the cited prior art),
wherein the upper cut-off wavelength is the wavelength at which the bandpass filter has a transmittance of 5% of the maximum transmittance of the bandpass filter, the upper cut-off wavelength being greater than a peak wavelength of the bandpass filter at which maximum transmittance occurs (e.g., ““… "transmission" means that the amount of light transmitted through the optical filter is 3% or more of the amount of light incident on the optical filter … full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in paragraphs 23 and 43), and
wherein the FWHM is a difference between the wavelengths at which the transmittance of the bandpass filter is at 50% of the maximum transmittance of the bandpass filter (e.g., “… full width at half maximum of the transmission spectrum of the light transmitted through the first optical filter 41 is preferably 80 nm or more and 300 nm or less …” in paragraph 43);
(b) receiving, by a processor, the output signal from the first infrared detector and a short path reference signal from a second infrared detector, wherein the light emitting diode and the second infrared detector are arranged such that a portion of the radiation emitted from the light emitting diode is transmitted along a second optical path through the sample chamber before being received by the second infrared detector, wherein a length of the first optical path through the sample chamber is at least twice a length of the second optical path through the sample chamber (e.g., see “… operation part 60 may include at least one of the drive part 70, a general-purpose processor that executes a function according to a program to be read, and a dedicated processor specialized for a specific process … based on the first detection signal output from the first light receiving part 51 … based on the second detection signal output from the second light receiving part 52 … first optical path length l1 is equal to or longer than the second optical path length l2 … first light source 31, the second light source 32, the first light receiving part 51 and the second light receiving part 52 may preferably be mounted on the same substrate …” in Fig. 1, Fig. 2, and paragraphs 85-87, 104, and 113 and a prima facie case of obviousness exists (MPEP § 2144.05) since the claimed at least twice range overlap the “longer than” range disclosed by the cited prior art);
(c) comparing, by the processor, the output signal and the short path reference signal (e.g., “… For example, the operation part 60 calculates the concentration of gas to be measured by subtracting the second attenuation amount from the amount obtained by multiplying the first attenuation amount by a proportional constant …” in paragraph 88); and
(d) determining, by the processor, the concentration of methane in the sample chamber based on the comparison of the output signal and the short path reference signal (e.g., “… non-dispersive infrared (NDIR) type device configured to measure the concentration of a gas … methane … equation (1) according to the Lambert-Beer law.
∆
I
=
I
0
1
-
e
-
e
c
l
(1), where I0 is the intensity of infrared light in the absence of gas in the optical path, e is a gas-specific absorption coefficient, c is concentration of gas, and l is an optical path length in a range where gas is present. From equation (1), it is clear that the attenuation amount ΔI of the intensity of infrared light by gas behaves exponentially … attenuation amount of the first intensity of infrared light by interference gas present in the first optical path L and the attenuation amount of the second intensity of infrared light by interference gas present in the second optical path L2 are in a proportionate relationship. Therefore, first, the operation part 60 subtracts the second attenuation amount from the amount obtained by multiplying the first attenuation amount by a proportional constant, and removes the attenuation amount of the first intensity of infrared light by interference gas present in the first optical path L1 and the attenuation amount of the second intensity of infrared light by interference gas present in the second optical path L2 to perform the interference removal operation in which the effect of infrared light by interference gas is removed … operation part 60 calculates the concentration of the gas to be measured by applying the concentration calculation table or the fitting of exponential function to the output after the interference removal operation in which the effect of infrared light absorption by interference gas is removed. It is preferable that the operation part 60 calculates the concentration of gas to be measured by using a polynomial of third order or higher in the equation (2) …” in paragraphs 26, 27, 90, 91, 122, 123, and 128).
The method of Isshiki et al. lacks the processor receiving an internal reference signal from a third infrared detector, comparing the output signal with the internal reference signal, and outputting an indication of the concentration of methane in the sample chamber, wherein the light emitting diode and the third infrared detector are arranged such that a portion of the radiation emitted from the light emitting diode is transmitted along a third optical path, and wherein the portion of the radiation received by the third infrared detector from the light emitting diode is received without being transmitted through the sample chamber and without being transmitted through the gas to be tested. However, “… NDIR …” is known to one of ordinary skill in the art (e.g., see (e.g., “… One of the most popular techniques for quantitative measurement of the industrially significant gases such as CO2, NOx, water vapor, methane etc. is carried out by optical absorption. Most of these gases have strong vibrational absorption spectra in the 1-12 µm region … nondispersive IR measurements (NDIR) … measurements are taken: color-1 incident on main detector, color-1 incident on reference detector … color-2 incident on reference 2 … goal of this system with four separate measurements is to compensate out these factors, and obtain a figure that is dependent only on gas concentration … define the ratio r1 as the ratio of main/reference detector signal for color-1 … a full-ratio, rf, can be defined as the ratio of r1 to r2 … rf can be used as a sensor output that, for a well-designed system, remains near 1 and for an ideal system, remains precisely 1 … In the presence of gas at concentration c, however, this full-ratio changes, via the transmission term … transmission as a function of concentration is described by Beer-Lambert Law … ASICs are used to process the detector signals while processing any necessary ratios … performance of processes or methods may utilize program instructions executable by a device (e.g., a computer, a processor, or other device) to perform, or control performance of, the processes or methods … a user interface include printers or display screens for visual presentation of output …” in paragraphs 97, 104, 196, 198, 199, 200, 202, 203, 240, 287, and 297 of Iutzi and “… non-dispersive infrared (NDIR) measurement have been recognized for many years as sensitive, stable and reliable methods of gas concentration measurement … in the detection of methane, the waveband of emitted radiation will be around 3.2 to 3.5 microns … first optical path A is approximately 3-4 times the length of the second optical path B. The relatively short length of the second optical path means that there is little interaction with the sample contained in the chamber 6 and, consequently, minimal absorption of radiation … optical fibre is arranged to receive a portion of the radiation emitted by source 3 and direct it, through the chamber 6, to detector 2. The optical fibre 9 constitutes optical path B. The remaining radiation which is not incident on fibre 9 passes on optical path A to detector 1. Since the whole of path B is contained within optical fibre 9, as in the FIG. 4a embodiment, there is no absorption on the reference channel …” in paragraphs 3, 55, 56, and 79 of Tkachuk). Therefore it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to provide a fiber coupled third infrared detector in the method of Isshiki et al. for obtaining an internal reference signal that is use by the processor to output a methane concentration based an output signal comparison, in order to achieve “no absorption on the reference channel” (as an improvement over “relatively short length of the second optical path means that there is little interaction with the sample contained in the chamber 6 and, consequently, minimal absorption of radiation”).
Claim(s) 2 and 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Isshiki et al. in view of Iutzi and Tkachuk as applied to claim(s) 1 above, and further in view of Spectrogon (Optical filters (3 February 2023), 11 pages, Retrieved from Internet: <web.archive.org/web/20230203060455/https://www.spectrogon.com/products/optical-filters/spectrogon-ab/bandpass-filters/>).
In regard to claim 2 which is dependent on claim 1, the system of Isshiki et al. lacks an explicit description of details of the “… optical filter 41 …” such as the maximum transmittance of the bandpass filter is at least 65%. However, “… optical filter …” details are known to one of ordinary skill in the art (e.g., see “… General Specifications: Diameter: 25.4 mm +0/-0.2 mm. Custom sizing Thickness: Specified in the filter list below (mm), tol ±0.2 mm Blocking: Avg < 0.1 % UV to block high Slope: < 5 % defined as:
%
S
l
o
p
e
=
λ
80
%
o
f
T
p
e
a
k
-
λ
c
λ
c
×
100
… Description: BP-CWL-HW in nanometers (HW 50 % Tpeak) Click on the Description, to see spectral characteristics for the filters in stock. … Description Substrate Thk CWL +/- tol HW +/- tol Transm >% Block high pc(s) in stock Price EUR 1-9 pcs … BP-3250-100 nm Quartz 0.5 20 20 70 30000 >10 418 …” on pp. 3-5 of Spectrogon). It should be noted that “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable results”. KSR International Co. v. Teleflex Inc., 550 U.S. 398 at 416, 82 USPQ2d 1385 (2007) at 1395 (citing United States v. Adams, 383 U.S. 39, 40 [148 USPQ 479] (1966)). See MPEP § 2143. In this case, one of ordinary skill in the art could have substituted a known conventional filter (e.g., commercially available “BP-3250-100 nm” filter with “70” “Transm >%”, in order to detect methane) for the unspecified filter of Isshiki et al. and the results of the substitution would have been predictable. Therefore it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to provide a known conventional filter (e.g., comprising details such as the maximum transmittance of the bandpass filter is at least 65%) as the unspecified filter of Isshiki et al.
In regard to claim 7 which is dependent on claim 1, the system of Isshiki et al. lacks an explicit description of details of the “… optical filter 41 …” such as the upper slope of the transmission spectrum of the bandpass filter or the lower slope of the transmission spectrum of the bandpass filter has an average gradient in the range of 0.5% to 1.5%; wherein the upper slope is the region between an upper shoulder wavelength that is greater than the peak wavelength and at which the transmittance of the bandpass filter is 80% of the maximum transmittance value of the bandpass filter and the upper cut-off wavelength, and the lower slope is the region between a lower cut-off wavelength and a lower shoulder wavelength that is smaller than the peak wavelength and at which the transmittance of the bandpass filter is 80% of the maximum transmittance value of the bandpass filter. However, “… optical filter …” details are known to one of ordinary skill in the art (e.g., see “… General Specifications: Diameter: 25.4 mm +0/-0.2 mm. Custom sizing Thickness: Specified in the filter list below (mm), tol ±0.2 mm Blocking: Avg < 0.1 % UV to block high Slope: < 5 % defined as:
%
S
l
o
p
e
=
λ
80
%
o
f
T
p
e
a
k
-
λ
c
λ
c
×
100
… Description: BP-CWL-HW in nanometers (HW 50 % Tpeak) Click on the Description, to see spectral characteristics for the filters in stock. … Description Substrate Thk CWL +/- tol HW +/- tol Transm >% Block high pc(s) in stock Price EUR 1-9 pcs … BP-3250-100 nm Quartz 0.5 20 20 70 30000 >10 418 …” on pp. 3-5 of Spectrogon). It should be noted that “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable results”. KSR International Co. v. Teleflex Inc., 550 U.S. 398 at 416, 82 USPQ2d 1385 (2007) at 1395 (citing United States v. Adams, 383 U.S. 39, 40 [148 USPQ 479] (1966)). See MPEP § 2143. In this case, one of ordinary skill in the art could have substituted a known conventional filter (e.g., commercially available “BP-3250-100 nm” filter with “Slope: < 5 % defined as:
%
S
l
o
p
e
=
λ
80
%
o
f
T
p
e
a
k
-
λ
c
λ
c
×
100
”, in order to detect methane) for the unspecified filter of Isshiki et al. and the results of the substitution would have been predictable. Therefore it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to provide a known conventional filter (e.g., comprising details such as the upper slope of the transmission spectrum of the bandpass filter or the lower slope of the transmission spectrum of the bandpass filter has an average gradient in the range of 0.5% to 1.5%; wherein the upper slope is the region between an upper shoulder wavelength that is greater than the peak wavelength and at which the transmittance of the bandpass filter is 80% of the maximum transmittance value of the bandpass filter and the upper cut-off wavelength, and the lower slope is the region between a lower cut-off wavelength and a lower shoulder wavelength that is smaller than the peak wavelength and at which the transmittance of the bandpass filter is 80% of the maximum transmittance value of the bandpass filter) as the unspecified filter of Isshiki et al.
Claim(s) 12 and 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Isshiki et al. in view of Iutzi and Tkachuk as applied to claim(s) 1 above, and further in view of Lützelschwab et al. (US 2020/0400556).
In regard to claims 12 and 13 which are dependent on claim 1, the system of Isshiki et al. lacks that a portion of the radiation transmitted through the bandpass filter is reflected by a second mirror along the second optical path through the sample chamber before being received by the second infrared detector. However, “… NDIR …” is known to one of ordinary skill in the art (e.g., see “… One of the most popular techniques for quantitative measurement of the industrially significant gases such as CO2, NOx, water vapor, methane etc. is carried out by optical absorption. Most of these gases have strong vibrational absorption spectra in the 1-12 µm region … nondispersive IR measurements (NDIR) … reflected off of mirror 830 … measure the incident light from the two optical paths which have differing path lengths, with the main detector path length being longer than the reference detector path length … measurements are taken: color-1 incident on main detector, color-1 incident on reference detector … color-2 incident on reference 2 … goal of this system with four separate measurements is to compensate out these factors, and obtain a figure that is dependent only on gas concentration … define the ratio r1 as the ratio of main/reference detector signal for color-1 … a full-ratio, rf, can be defined as the ratio of r1 to r2 … rf can be used as a sensor output that, for a well-designed system, remains near 1 and for an ideal system, remains precisely 1 … In the presence of gas at concentration c, however, this full-ratio changes, via the transmission term … transmission as a function of concentration is described by Beer-Lambert Law … ASICs are used to process the detector signals while processing any necessary ratios … performance of processes or methods may utilize program instructions executable by a device (e.g., a computer, a processor, or other device) to perform, or control performance of, the processes or methods … a user interface include printers or display screens for visual presentation of output …” in paragraphs 97, 104, 189, 196, 198, 199, 200, 202, 203, 240, 287, and 297 of Iutzi and “… When a specie of interest is introduced into the measurement chamber, it absorbs a portion of the infrared light, causing the signal output by each IR sensor to drop. Since the measurement path is longer than the reference path, more IR light is absorbed therein, causing the IR sensor associated with this path to receive proportionally less IR light than the sensor associated with the reference path. The difference in, and/or the ratio of, the outputs of the two sensors can hence be exploited to measure not only the presence but also the concentration of the specie of interest present in the measurement chamber. This principle is well-known … ratio L1/L2 is typically between 4/5 and 1/5, preferably between 1/3 and 2/3 …” in paragraphs 5 and 40 of Lützelschwab et al.). Therefore it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to provide a second mirror positioned along the second optical path and configured to reflect radiation from the light emitting diode to the second infrared detector, wherein the light emitting diode, the bandpass filter and the second infrared detector are arranged such that a portion of the radiation emitted from the light emitting diode is transmitted through the bandpass filter and along the second optical path through the sample chamber, before being received by the second infrared detector in the system of Isshiki et al., in order to achieve “compensate out these factors, and obtain a figure that is dependent only on gas concentration”.
Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Iutzi (US 2024/0405148) in view of Tkachuk (US 2009/0268204).
In regard to claim 20, Iutzi discloses a system for detecting a concentration of a target gas in a gas sample, comprising:
(a) a sample chamber for containing the gas sample (e.g., see Figs. 8A-B and “… gas detection chamber …” in paragraph 188);
(b) an infrared light emitting diode arranged to emit infrared radiation into the sample chamber (e.g., see “… One of the most popular techniques for quantitative measurement of the industrially significant gases such as CO2, NOx, water vapor, methane etc. is carried out by optical absorption. Most of these gases have strong vibrational absorption spectra in the 1-12 µm region … nondispersive IR measurements (NDIR) … dual wavelength LED 810 … As can be appreciated by one skilled in the art, the selected wavelength is chosen such that it may be absorbed by a gas which is to detected … in this example, for CH4 detection around 4.3 µm wavelength …” in Figs. 8A-B and paragraphs 97, 104, 185, 190, and 221);
(c) a first infrared detector configured to produce an output signal based on the radiation it receives (e.g., see “… main detector 860 …” in Figs. 8A-B and paragraph 185);
(d) a second infrared detector configured to produce a short path reference signal based on the radiation it receives (e.g., see “… reference detector 840 …” in Figs. 8A-B and paragraph 185);
(e) a third infrared detector configured to produce an internal reference signal based on the radiation it receives, wherein the light emitting diode and the third infrared detector are arranged such that a portion of the radiation emitted from the light emitting diode is received by the third infrared detector from the light emitting diode (e.g., see “… measuring the photocurrent in each active region independently … reference detector 840 …” in Figs. 8A-B and paragraphs 25 and 185 or “… at least one detector acts as a reference detector…” in paragraph 67);
(f) a first mirror positioned along a first optical path and configured to reflect radiation from the light emitting diode to the first infrared detector, wherein the light emitting diode, the first mirror and the first infrared detector are arranged such that a portion of the radiation emitted from the light emitting diode is transmitted along the first optical path through the sample chamber, reflected by the first mirror and received by the first infrared detector (e.g., see “… Mirror 850 helps focus the incident collimated light onto the main detector 860 … measure the incident light from the two optical paths which have differing path lengths, with the main detector path length being longer than the reference detector path length …” in Figs. 8A-B and paragraphs 189 and 196);
(g) a second mirror positioned along a second optical path and configured to reflect radiation from the light emitting diode to the second infrared detector, wherein the light emitting diode, the second mirror and the second infrared detector are arranged such that a portion of the radiation emitted from the light emitting diode is transmitted along the second optical path through the sample chamber, reflected by the second mirror and received by the second infrared detector (e.g., see “… reflected off of mirror 830 … measure the incident light from the two optical paths which have differing path lengths, with the main detector path length being longer than the reference detector path length …” in Figs. 8A-B and paragraphs 189 and 196), wherein the first optical path length is at least twice the second optical path length (i.e., a prima facie case of obviousness exists (MPEP § 2144.05) since the claimed “at least twice” range lie inside the “longer than” range disclosed by the cited prior art); and
(h) a processor, wherein the processor is configured to:
receive the output signal from the first infrared detector, the short path reference signal from the second infrared detector and the internal reference signal from the third infrared detector (e.g., “… ASICs are used to process the detector signals while processing any necessary ratios …” in paragraph 240);
compare the output signal with the short path reference signal (e.g., “… measurements are taken: color-1 incident on main detector, color-1 incident on reference detector … define the ratio r1 as the ratio of main/reference detector signal for color-1 …” in paragraphs 196 and 199);
compare the output signal with the internal reference signal (e.g., “… measurements are taken: … color-2 incident on reference 2 … r2 as the ratio of main/reference detector signal for color-2 … a full-ratio, rf, can be defined as the ratio of r1 to r2 …” in paragraphs 196, 199, and 200);
determine the concentration of methane in the sample chamber based on the comparison of the output signal and the short path reference signal and/or the comparison of the output signal and the internal reference signal (e.g., “… methane … goal of this system with four separate measurements is to compensate out these factors, and obtain a figure that is dependent only on gas concentration … rf can be used as a sensor output that, for a well-designed system, remains near 1 and for an ideal system, remains precisely 1 … In the presence of gas at concentration c, however, this full-ratio changes, via the transmission term … transmission as a function of concentration is described by Beer-Lambert Law …” in paragraphs 97, 198, 202, and 203); and
output an indication of the concentration of methane in the sample chamber (e.g., “… ASICs are used to process the detector signals while processing any necessary ratios … performance of processes or methods may utilize program instructions executable by a device (e.g., a computer, a processor, or other device) to perform, or control performance of, the processes or methods … a user interface include printers or display screens for visual presentation of output …” in paragraphs 240, 287, and 297).
The system of Iutzi lacks that a portion of the radiation emitted from the light emitting diode is received by the third infrared detector without being transmitted through the gas sample and without being reflected by a mirror. However, “… NDIR …” is known to one of ordinary skill in the art (e.g., see “… non-dispersive infrared (NDIR) measurement have been recognized for many years as sensitive, stable and reliable methods of gas concentration measurement … in the detection of methane, the waveband of emitted radiation will be around 3.2 to 3.5 microns … first optical path A is approximately 3-4 times the length of the second optical path B. The relatively short length of the second optical path means that there is little interaction with the sample contained in the chamber 6 and, consequently, minimal absorption of radiation … optical fibre is arranged to receive a portion of the radiation emitted by source 3 and direct it, through the chamber 6, to detector 2. The optical fibre 9 constitutes optical path B. The remaining radiation which is not incident on fibre 9 passes on optical path A to detector 1. Since the whole of path B is contained within optical fibre 9, as in the FIG. 4a embodiment, there is no absorption on the reference channel …” in paragraphs 3, 55, 56, and 79 of Tkachuk). Therefore it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to provide an optical fiber in the system of Iutzi so that a portion of the radiation emitted from the light emitting diode is received by the third infrared detector without being transmitted through the gas sample and without being reflected by a mirror, in order to achieve “no absorption on the reference channel” as an improvement over “relatively short length of the second optical path means that there is little interaction with the sample contained in the chamber 6 and, consequently, minimal absorption of radiation”.
Response to Arguments
Applicant’s arguments with respect to the amended and new claims have been fully considered but are moot in view of the new ground(s) of rejection.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 4,507,558 teaches gas detection.
US 2002/0050567 teaches gas detection.
US 2003/0090670 teaches gas detection.
US 2013/0342680 teaches gas detection.
US 2021/0102840 teaches gas detection.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 Shun Lee whose telephone number is (571)272-2439. The examiner can normally be reached Monday-Friday.
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/SL/
Examiner, Art Unit 2884
/UZMA ALAM/Supervisory Patent Examiner, Art Unit 2884
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