Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on January 21, 2025, March 12, 2025 and March 27, 2026 has been considered by the examiner.
Election/Restrictions
Claims 10-14 and 16-18 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on May 20th, 2026 and June 8, 2026.
Examiner’s Note
It is noted that applicant’s invention is directed to detecting gas leaks, such as hydrogen leaks, which was found by the applicants to be substantially free of water vapor, by taking an image at a wavelength around 1.3-1.6 microns where these wavelengths are highly absorbed by water vapor, and seeing, effectively, the shadow caused by the hydrogen, and thus detecting the leak of hydrogen (so-called negative image or inverse BAGI). However, the claims are extremely broad, and do not limit the claims to applicant’s invention. The claims do not limit the wavelengths to those where the water vapor would have the highest absorption, therefore, any gas found in the ambient air (including CO2, water vapor, oxygen, or even other gases of the leaked plume) that has a generally measurable non-zero feature in this wavelength range would read on this limitation. The claims call for monitoring backscattered light to collect an absorption image of a plume of gas having an absorption less than that of the absorption feature delineated by a surrounding gas with the absorption feature; however, it is not disclosed how this is related to the wavelengths selected, and it appears that this could read on any image that contains a plurality of gases wherein at least one of the gases has an absorption less than the absorption of another gas within the image, which is inherent to all contrast/differential absorbance images, which rely on differing absorbances to show the different materials within the image. And finally, there is no disclosure in the claims that the leak is detected; the image information is just displayed. Because of this, many different gas imaging techniques can read on the claims as currently written, and are applied below. Applicant is encouraged to further define the claims to align them with their invention.
Claim Objections
Claims 7-8 are objected to because of the following informalities: These claims reference “the plume of dry gas” which is inconsistent with the wording of claim work “a plume of gas”. Appropriate correction is required.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1-3 is/are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Kulp et al. (US 2002/0071122).
With regards to claim 1, Kulp discloses a method of imaging (abstract) comprising: (a) illuminating a gas volume with light (via fig. 1, 10) providing a narrowband wavelength between .93-4.4 microns (⁋ 53, capable of operating at wavelengths between 1.3-4.5 microns which substantially overlaps claimed range) in a range including a measurable absorption feature present in ambient air (as can be seen in fig. 2 and 4, and as discussed in ⁋ 54, ambient air has a nonzero, and therefore measurable absorption feature); (b) monitoring backscattered light (via 16 ⁋ 54) to collect an absorption image (as can be seen on 18) of a plume of gas (12) having an absorption less than that of the absorption feature delineated by a surrounding gas with the absorption feature (fig. 4, and ⁋ 26, when illuminated with the off laser wavelength, the gas plume doesn’t absorb, but the ambient air still shows a measurable absorption feature which would be more than the absorption feature of the gas) ; and (c) displaying image information from the absorption image (via 18- video image of plume).
In regards to claim 2, the method comprises varying the wavelength of the illumination for different locations in the absorption image according to signal strength to improve signal-to-noise ratio of the monitored backscattered light (⁋ 109).
In regards to claim 3, Kulp further teaches prior to (c), characterizing the backscattered light absent absorption by the gas volume to correct the absorption image for variations in backscatter light (⁋ 26 and 59, descriptions of differential imaging).
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.
Claim(s) 1, 3-6 and 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bennett et al. (US 2019/0376890) in view of Waxman et al. (US 2017/0336281).
With regards to claim 1, Bennett discloses a method of imaging (abstract) comprising: (a) illuminating a gas volume with light (via fig. 4, 208b) providing a narrowband wavelength in a range including a measurable absorption feature present in ambient air (⁋ 30, the second wavelength is chosen to both not be significantly absorbed by the gas of interest and also be absorbed by known or expected constituent gases within the ambient environment); (b) monitoring backscattered light (via 224) to collect an absorption image (⁋ 33 the detector may comprise an imaging detector to detect amplitude map of returned light) of a plume of gas (fig. 1, 122) having an absorption less than that of the absorption feature delineated by a surrounding gas with the absorption feature (⁋ 30) ; and (c) displaying image information from the absorption image (⁋ 8 and ⁋ 35). Bennett is silent to the specific narrowband wavelength chosen to illuminate the measurable absorption feature present in ambient air. However, it is disclosed that the second wavelength of illumination should be selected to be absorbed by known or expected constituent gases within the ambient environment (⁋ 30). Further, the examiner takes official notice, that water vapor and carbon dioxide are well known constituents of ambient air, and would be expected within an open air environment.
Waxman generally teaches some of the absorption peaks of water vapor and carbon dioxide are found in the 1.8-2.5 micron range (fig. 2A, ⁋ 51). Therefore, it would be obvious to one of ordinary skill in the art to have the narrowband wavelength of Bennett be chosen to be between .93-4.4 microns, as taught by Waxman, in order to allow the second wavelength of illumination, to be selected to be absorbed by known or expected constituent gases of water vapor and carbon dioxide of the ambient environment.
In regards to claim 3, Bennett further teaches prior to (c), characterizing the backscattered light absent absorption by the gas volume to correct the absorption image for variations in backscatter light (fig. 5, 510-512 and ⁋ 34).
In regards to claim 4, Bennett further discloses the characterization of backscattered light determines a distance related to a location of back scattering (⁋ 21, “In the case of a system 104 incorporating a type of LIDAR, information regarding the time of flight of the light is used to obtain range information between the sensor system 104 and the target area 114 within the scene 112.”).
In regards to claim 5, Bennett further discloses the distance is provided by LIDAR imaging (⁋ 21).
In regards to claim 6, Bennett further discloses that the step of illuminating uses a scanned laser (lasers 310 and 330 ⁋ 29 are scanned using steering mirror 220) modulated for LIDAR phase ranging (⁋ 21).
In regards to claim 9, the absorption feature is water vapor (as discussed above).
Claim(s) 7-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bennett et al. (US 2019/0376890) in view of Waxman et al. (US 2017/0336281) and further in view of Reed et al. (2024/0418742).
In regards to claim 7-8, the combination discloses the method of imaging gas, as discussed above. The combination is silent to analyzing the absorption image to determine an optical flow of the plume of dry gas and applying the absorption image to a model of gas dynamics to deduce a volume flow rate of the plume of dry gas.
Reed, in the same field of endeavor of Bennett of identifying gas flow using LIDAR systems (abstract), discloses analyzing an obtained absorption image (⁋ 46) to determine an optical flow of the plume of dry gas and applying the absorption image to a model of gas dynamics to deduce a volume flow rate of the plume of dry gas (⁋ 9 and fig. 2). Reed discloses that this method is particularly useful for the remote detection of location and quantification of leaks (abstract). Therefore, it would be obvious to one of ordinary skill in the art to include into the combination the steps of analyzing the absorption image to determine an optical flow of the plume of dry gas and applying the absorption image to a model of gas dynamics to deduce a volume flow rate of the plume of dry gas, as taught by Reed, in order to help identify the location and quantification of remote gas leaks.
Additional Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. The prior art of Huang et al. discloses identifying hydrogen gas leaks by using a surrounding gas that has a higher and measurable absorption feature also present in the air.
Conclusion
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/KARA E. GEISEL/
Art Unit 2877
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