DETAILED ACTION
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph 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.
Claims 1-9 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), 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 applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 recites the product of the time period and the linear speed is at least 13.6 (m). The specification does not appear to offer support for this limitation. The one example in the specification that provides for a product value of 13.6 is a comparative example that resulted in unmelted areas of preform. In paragraph [0006] of the PgPub, the unmelted areas are unwanted. Furthermore, it is evident that the intention of the invention is to have a product value of at least 15.5 (m) or more (see abstract), even preferably more than 21.7 (m), see [0009]. Accordingly, it does not appear the applicant has support for the invention to provide for a product value of at least 13.6 (m).
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.
Claims 13-18 and 20-21 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kanamori et al. (JP H02149442 as provided for by applicant). Regarding claims 13-15 and 18, Kanamori discloses a manufacturing method for an optical fiber preform, comprising manufacturing a glass fine particle deposit (soot preform) by injecting glass fine particles generated with a burner for glass fine particle synthesis onto a starting material rotating around its central axis as an axis of rotation (lines 17-19 on page 1), and sintering the soot preform to vitrify it into transparent glass by suspending and heating the glass fine particle deposit in a furnace core tube (figures, lines 70-77 on page 2). Kanamori further teaches in example 2, performing sintering by lowering the preform into a heating zone of the furnace core tube, the zone having a height of 200mm (lines 8-9 on page 4), at a rate of 4 mm/min (which is less than 7.0 m/min), which provides for a time period during which a part of the soot preform is heated in the heating zone of the furnace core tube of 50 mins (200mm/4mm/min), while flowing helium gas in the furnace core tube at a rate of 10 l/min (last 3 lines of first paragraph on page 4), the furnace core tube having an inner diameter of 140mm (line 7 on page 4), which provides for a linear speed of the sintering gas of 0.649 m/min, wherein a product of the time period and the linear speed is 32.5 m, which is greater than 21.7m and less than 34.1 m.
Regarding claim 16, Kanamori teaches sintering of the soot preform to vitrify it into transparent glass comprises heating the soot preform by lowering the preform through a heating zone in the furnace core tube (“porous preform is heated by passing it through a high temperature region formed by ring-shaped heater “ at bottom of page 1, “porous glass preform supported at its upper end…being inserted into a heating furnace” at lines 70-77 on page 2, “drop rate of 8mm/ min” in line 202 on page 4, figures).
Regarding claim 17, Kanamori teaches supplying helium gas as sintering gas (lines 201-202 on page 4).
Regarding claim 19, as described in the example above, the time period is calculated to be 50 mins.
Regarding claim 20, as described in the example above, the linear speed of the sintering gas flowing in the furnace core tube is calculated to be 0.649 m/min, which is greater than 0.36 m/min.
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.
Claims 1-9 are rejected under 35 U.S.C. 103 as being unpatentable over Lane et al. (4,741,748) in view of Grieco et al. (2023/0382781). Regarding claim 1, Lane teaches a conventional method for producing optical fiber preform comprising manufacturing a glass fine particle deposit (porous glass preform) by an outside vapor deposition process which typically involves injecting glass fine particles generated with a burner for glass fine particle synthesis onto a starting material rotating around its central axis as an axis of rotation (col. 1 lines 14-16), and sintering the soot preform to vitrify it into transparent glass by suspending and heating the glass fine particle deposit in a furnace core tube, while flowing a sintering gas in the furnace core tube (col. 1 lines 21-40, 48-53). Lane further teaches the sintering is performed by lowering the preform into a heating zone of the furnace core tube, the zone having a height of 26cm (col. 1 lines 34-37), at a rate of 5 mm/min, which provides for a time period during which a part of the soot preform is heated in the heating zone of the furnace core tube of 52 mins (260mm/5mm/min). Lane teaches the furnace core tube having an inner diameter of 12.7cm (col. 1 line 29-32) and flowing a mixture of gases comprising chlorine and helium in the furnace core tube (col. 1 lines 21-26, col. 6 lines 31-43), but doesn’t specify a flow rate of the gas. Grieco teaches the quality of consolidated optical fiber preforms depends on factors including the gas flow of helium during processing of the preform, as defects in the drawn fiber can be attributed to the presence of air due to an insufficient flow of helium gas within the furnace ([0013]). Like Lane, Grieco teaches sintering the preform to vitrify it into transparent glass by suspending and heating the preform in a furnace core tube, while flowing a sintering gas in the furnace core tube ([0017], [0018]). Grieco further teaches it is typical to employ a helium flow rate during sintering of 20 slpm to 40 slpm ([0016]) and provides examples using 25 slpm, 30 slpm, and 40 slpm of helium gas in table 1. Such flow rates in the furnace of Grieco having an inner diameter of 330 mm provides for a linear speed of the helium gas in the range of 0.234 m/min to 0.468 m/min (i.e. 0.234 m/min at 20 slpm, 0.292 m/min at 25 slpm, and 0.351 m/min at 30 slpm). Grieco teaches satisfactory sintering of the preform is obtained using typical helium gas flow as these ([0189]). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have tried similar linear speeds in the range of 0.234 m/min to 0.468 m/min, such as 0.292 m/min or 0.351 m/min, for the sintering gas (helium) in the method of Lane, as Grieco teaches a reasonable expectation of success in sintering of the preform while minimizing defects in the drawn fiber. In applying a linear speed of helium gas as that of Grieco for the sintering of the preform in the method of Lane, with a time period of 52 minutes in the heating zone, the product of the time period and a linear speed of 0.292 m/min is 15.2 (m) and the product of the time period and a linear speed 0.351 m/min is 18.2.(m), which overlaps with the claimed range of 13.6 (m) to 18.1 (m).
Regarding claims 2-3 and 6, Grieco exemplifies a linear speed for the helium gas of 0.351 m/min (at 30 slpm), which would provide for a product of the time period and a linear speed of 18.2.(m), which is considered close enough to 18.1 (m). Naturally, since the suggested range of linear speeds is 0.234 m/min to 0.468 m/min, it would be obvious to one of ordinary skill in the art to expect a product value of 18.1 to be included.
Regarding claim 4, Lane teaches sintering of the soot preform to vitrify it into transparent glass comprises heating the soot preform by lowering the preform through a heating zone in the furnace core tube (col. 1 lines 47-52).
Regarding claim 5, Grieco teaches supplying helium gas as sintering gas ([0016], [0188]).
Regarding claim 7, as described above in the example of Lane, the time period is calculated to be 52 mins.
Regarding claim 8, as discussed above, Grieco teaches the linear speed of the sintering gas flowing in the furnace core tube is calculated to be in the range of 0.234 m/min to 0.468 m/min, which include values that are greater than 0.36 m/min.
Regarding claim 9, Lane teaches the sintering temperature is 1450°C, or about 1500°C (col. 1 lines 24, 50-51). Grieco teaches sintering temperatures can be set in the range of 1450°C to 1600°C ([0116]). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have applied a sintering temperature in the range of 1450° to 1600°C, which overlaps with the claimed range of 1555°C -1605°C, as Grieco teaches they are common and well-known sintering temperatures for optical fiber preforms, that predictable provides for successful vitrification of the preforms.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Kanamori et al. (JP H02149442 as provided for by applicant). Kanamori exemplifies a sintering temperature of 1680°C (line 202 on page 4), but also teaches it is well known to sinter at a temperature of about 1600°C (lines 24-26 on page 1), which is within the claimed range of 1555°C-1605°C. Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have tried an alternative sintering temperature, such as 1600°C, as Kanamori teaches the predictable sintering of the soot preform with a reasonable expectation of success, as it is well known in the art.
Response to Arguments
Applicant’s arguments, filed March 18, 2026, with respect to the rejection(s) of claim 1 under Kanamori have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Lane and Grieco.
Regarding new claim 13, Kanamori teaches in example 2, a lowering rate of 4 mm/min, which is less than 8mm/min.
Conclusion
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 QUEENIE S DEHGHAN whose telephone number is (571)272-8209. The examiner can normally be reached Monday-Friday 8:00-4:30.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Alison Hindenlang can be reached at 571-270-7001. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/QUEENIE S DEHGHAN/Primary Examiner, Art Unit 1741
Prosecution Insights