DETAILED ACTION
Specification
The lengthy specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 4 and 16 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 4 recites supplying a halogen compound gas into a core tube with the resonator in the preheating and the heating with the microwave. However, claim 4 depends on claim 1, which recites the preheating is performed with a non-microwave heater. Thus, there is a contradiction between preheating without a microwave heater in claim 1 and preheating in a core tube with a microwave resonator in claim 4.
Claim 16 recites relative placement of the resonator to the non-microwave heater. Claim 16 also recites a moving direction of the porous body in a core tube. It is unclear how the core tube is related to the resonator or the non-microwave heater.
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, 2, 10, and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Tanaka et al. (JP01-183436 as provided for by applicant) in view of Sato et al. (JP 4403082 machine translation provided). Tanaka teaches a method for manufacturing a silica glass body comprising preheating a porous silica glass body (“preheat the preform” in example 1 on page 6), and placing the preheated porous silica glass body in a resonator (2nd passage on page 6) that resonates a microwave having a frequency band of 2GHz-4GHz (bottom of page 5), which falls within the claimed range of 1GHz to 30 GHz, to heat the porous silica glass body with the microwave (example 1 on page 6), wherein at least a part of the porous silica glass body contains an additive other than silicon and oxygen (top of page 6), wherein the porous silica body is preheated to a temperature equal to or higher than a glass transition temperature of the additive-added portion of the porous silica glass body in the preheating (i.e. 1500°C top passage on page 5), and wherein the porous silica glass with the additive is heated with the microwave in the heating with the microwave (example 1 on page 6). Tanaka suggests the additive is added in the making of the porous glass body, which is before the preheating step (example 1 on page 6). Tanaka teaches traditional preheating using a burner results in non-uniform heating of the preform (bottom of page 6). Tanaka further teaches preheating using a thermal plasma instead to provide efficient heating without contamination (page 7), but doesn’t suggest other heating sources. Sato teaches a method for producing a silica glass body comprising providing porous glass preform ([0001]-[0002]) and preheating the porous glass body ([0059], [0045]). Sato teaches heating can be performed using flame heating or electric heating. Sato teaches electrical means include infrared radiation, resistance heating, and induction heating. Sato teaches flame heating can react with the glass and electric heating is preferred because it avoids reaction with the glass ([0045]). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have to try other heating means, such as electrical heating, as it is a known alternative for heating a preform, while also preventing reaction with the glass and uniform heating of the glass preform with a reasonable expectation of success.
Regarding claim 2, Tanaka teaches the additive includes fluorine (top of page 6).
Regarding claim 10, Tanaka teaches the porous silica glass body is made with additives, such as fluorine (top of page 6) and inserting the doped porous silica glass body into the furnace for preheating (example 1 on page 6).
Regarding claim 15, Sato teaches electrical heating includes infrared heating, resistance heating, and induction heating ([0045]).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Tanaka et al. (JP01-183436 as provided for by applicant) and Sato et al. (JP 4403082 machine translation provided) as applied to claim 2 above, and further in view of Toko et al. (JP 2005-053740 as provided for by applicant). Tanaka teaches adding a halogen additive to the porous glass body, but doesn’t specify doing so in a preheating step. In a similar field of endeavor, Toko discloses a method for manufacturing a silica glass body comprising preheating a porous silica glass body (second heat treatment [0027], [0045]), and placing the preheated porous silica glass body in microwave heating apparatus a microwave operating at a frequency band of 28GHz, which falls within the claimed range of 1GHz to 30 GHz ([0043]) to heat the porous silica glass body with the microwave (third heat treatment [0022], [0030]), wherein at least a part of the porous silica glass body contains an additive (i.e. fluorine) other than silicon and oxygen, wherein the porous silica body is preheated to a temperature equal to or higher than a glass transition temperature of the additive-added portion of the porous silica glass body in the preheating ([0028]), and wherein the porous silica glass with the additive is heated with the microwave in the heating with the microwave ([0030], [0046]). Toka further teaches the additive, such as fluorine, can be added during preheating so as to replace defects in the porous body with Si-F bonds ([0020], [0027]). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided the fluorine additive in the preheating step in the method of Tanaka, as it would further provide for the removal of defects by forming Si-F bonds in the glass body, as taught by Toko.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Tanaka et al. (JP01-183436 as provided for by applicant) and Sato et al. (JP 4403082 machine translation provided), as applied to claim 2 above, and further in view of Toko et al. (JP 2004115299 machine translation provided, which be referred to as Toko ‘299). Tanaka further teaches the microwave heating apparatus comprises a core tube 2 including the resonator and supplying a gas into the core tube during the preheating step and heating with microwave step (bottom paragraph on page 4, top paragraph on page 5), but doesn’t specify a halogen compound gas. In a similar field of endeavor, Toko ‘299 teaches a method for producing a silica glass body, and like Takana is doped with fluorine. Toko teaches adding the dopant by heating a porous silica glass body with microwave energy while flowing a dopant gas during preheating and vitrification ([0010]-[0011], [0029]), wherein the dopant gas includes a halogen compound gas, such as SiF4 ([0031]). Toko teaches this provides for a homogenous silica glass body due to uniform heating ([0023]) with a uniform refractive index distribution ([0025], [0032]). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have supplied the halogen element (dopant) in the preheating and heating steps, when microwave heating is being used, so as to provide for uniform doping and heating of the porous glass body, as taught by Toko. In applying this teaching to Tanaka, the halogen compound gas would be supplied to the core tube with the resonator of Tanaka during preheating and heating with the microwave.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Tanaka et al. (JP01-183436 as provided for by applicant) and Sato et al. (JP 4403082 machine translation provided), as applied to claim 1 above, and further in view of Gomatam et al. (2023/0061100). Tanaka teaches the glass preform comprises silica and fluorine as an additive, but doesn’t specify a glass transition temperature. Gomatam teaches the glass transition temperature for silica doped with fluorine is about 790°C ([0016]), which is within the range of 700°C-1100°C. Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have expected a similar glass transition temperature of 790°C for the glass body of Tanaka as it comprises similar components.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over ibi Tanaka et al. (JP01-183436 as provided for by applicant) and Sato et al. (JP 4403082 machine translation provided), as applied to claim 1 above, and further in view of Hibino et al. (JP 62-123036 machine translation provided). Tanaka teaches preheating with thermal plasma and subsequently heating with microwave within the same zone of the apparatus (figures 1A-1C, bottom half of page 4). Tanaka teaches extra steps are required for transitioning to microwave heating, including the removal of the plasma gas and replacing it with a different gas. Tanaka further teaches the porous glass body moves in a downward direction within a core tube 2 (figures 1A-1C, bottom half of page 4). However, Tanaka doesn’t suggest an arrangement wherein the microwave heater is located downstream of the thermal plasma heating area. Like Tanaka, Hibino teaches a method for manufacturing a silica glass body comprising preheating a porous silica glass body with a non-microwave heater, and then subsequently heating the porous body with microwave to sintering the porous glass body, wherein the non-microwave heater includes a resistance heater (abstract). Hibino further teaches arranging the microwave heater downstream of the non-microwave heater in a direction in which the porous body is moved, i.e. in a vertical direction (2nd paragraph on page 2). Naturally, arranging the non-microwave heater and the microwave heater in series allows for the glass body to successively preheated and heated in a continuous and efficient manner, to form the sintered glass body, as seen in figures 1 and 2. Hibino teaches this arrangement allows for the preheating of the porous glass body to a temperature that allows for the easier heating with microwaves (paragraph bridging pages 1 and 2). Hibino teaches this also prevents overheating of the surface of the glass body and allows for easier removal of hydroxyl groups in the glass body (top two paragraphs on page 2). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided for the arrangement of the preheating heater and the microwave heater in series as an alternative to the singular heating zones of Tanaka, as it would provide for a more efficient and continuous processing of the porous glass body without the need to purge or change the gaseous environment of the heating zone, as is required in Tanaka.
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Tanaka et al. (JP01-183436 as provided for by applicant) and Sato et al. (JP 4403082 machine translation provided), as applied to claim 1 above, and further in view of Ooga et al. (JP 2808857 machine translation provided). Tanaka is silent regarding other halogen additives. Ooga teaches a method for producing a glass body comprising providing a porous silica glass body and heat treating the porous preform. Ooga teaches the heat treatment comprises heating in an atmosphere including a chlorine-based gas and a fluorine-based gas, wherein both gases work to dehydrate and dope the porous body, and further heating to sinter the preform (page 1, 4th paragraph on page 2). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have further provided for chlorine as an additive so as to assist in the dehydration and removal of water of the porous glass body.
Response to Arguments
Applicant’s arguments filed July 21, 2026, with respect to the rejection(s) of claim 1 under Tanaka, as well as under Toko and Hu, 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 Tanaka and Sato.
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.
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/QUEENIE S DEHGHAN/Primary Examiner, Art Unit 1741
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