DETAILED ACTION
Election/Restrictions
Applicant’s election without traverse of group I, claims 1-10, in the reply filed on June 26, 2026 is acknowledged.
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 5-6 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.
Claims 5 and 6 recite the limitation "the soot" in line 3. There is insufficient antecedent basis for this limitation in the claim.
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 1-2, 4, and 8 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Ishikawa et al. (5,895,515). Ishikawa discloses a method of manufacturing an optical fiber preform comprising forming a core by blowing a first raw material gas from a core burner to a starting base material (col. 7 lines 7-14), and forming a first clad by blowing a second raw material gas from a clad burner to the core (col. 7 lines 14-17), after forming the first clad, forming a second clad by blowing a third raw material gas (having more CF4 gas) from the clad burner to an end portion of the core (col. 7 lines 23-36, fig. 5), forming a core rod by heating the first clad and second clad (col. 7 lines 39-54, figs. 6-7), and forming a third clad on an outer periphery of the core rod (col. 7 lines 64-67, col. 8 lines 1-7, fig. 9).
Regarding claim 2, the flow rate of silicon tetrafluoride in the third raw material gas is greater than a flow rate of the silicon tetrafluoride in the second raw material gas (col. 7 lines 25-36).
Regarding claim 4, as just mentioned the flow rate of silicon tetrafluoride is increased linearly as the glass soot grows axially. Ishikawa further teaches the preform is grown for 800mm (col. 7 lines 37-38). Thus, the flow rate of third raw material gas is blown to a region of larger than 5cm and smaller than 20cm from the end portion of the core.
Regarding claim 8, Ishikawa teaches the variation in a relative refractive index difference in a longitudinal direction of the optical fiber preform is smaller than 0.0021% (col. 10 lines 5-13, fig. 12).
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 3 is rejected under 35 U.S.C. 103 as being unpatentable over Ishikawa et al. (5,895,515). Ishikawa teaches the flow rate of silicon tetrafluoride is increased linearly from 50 SCCM to 100 SCCM (or from 50 SCCM to 125 SCCM) as deposition proceeds in the axial direction (col. 7 lines 34-35, col. 8 lines 35-37). Accordingly, at one point of deposition, the flow rate of silicon tetrafluoride is in the range of 53 SCCM to 76 SCCM, which is 1.3-1.9 times lower than the final flow rate of 100 SCCM. Thus, it would have been obvious to one of ordinary skill in the art at the time of the invention to have expected the flow rate of the silicon tetrafluoride in the third raw material gas (toward the end of deposition) to be greater than 1.3 times and less than 1.9 times a flow rate of the silicon tetrafluoride in the second raw material (at an earlier point of deposition), as Ishikawa teaches the flow rate is increased linearly as the glass soot grows axially.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Ishikawa et al. (5,895,515) as applied to claim 1 above, and further in view of Nakajima (2015/0040616). Ishikawa teaches the flow rate of silicon tetrafluoride is increased linearly from 50 SCCM to 100 SCCM as deposition of soot proceeds in the axial direction (col. 7 lines 34-35). Accordingly, at one point of deposition, the flow rate of silicon tetrafluoride is in the range of 53 SCCM to 76 SCCM, which is 1.3-1.9 times lower than the final flow rate of 100 SCCM. However, Ishikawa does not specify a density of the soot formed. Nakajima teaches a similar method for producing an optical fiber preform comprising forming a core and cladding soot layers by a vapor axial deposition process ([0020]). Nakajima further teaches the cladding soot layer should have a bulk density of at least 0.25g/cm3 ([0028]), which falls within the claimed range of 0.25 g/cm3 to 0.35g/cm3. Nakajima teaches a density of 0.25g/cm3 is required to ensure sufficient strength in the preform to prevent cracking in clad soot layer. Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided for a similar density for the soot formed in the forming the first clad and second clad, so as to ensure sufficient strength to prevent cracking, as taught by Nakajima.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Ishikawa et al. (5,895,515) as applied to claim 1 above, and further in view of Nakajima (2015/0040616). Ishikawa teaches the flow rate of silicon tetrafluoride is increased linearly from 50 SCCM to 100 SCCM as deposition of soot proceeds in the axial direction (col. 7 lines 34-35). Accordingly, at one point of deposition, the flow rate of silicon tetrafluoride is in the range of 53 SCCM to 62 SCCM, which is 1.6-1.9 times lower than the final flow rate of 100 SCCM. However, Ishikawa does not specify a density of the soot formed. Nakajima teaches a similar method for producing an optical fiber preform comprising forming a core and cladding soot layers by a vapor axial deposition process ([0020]). Nakajima further teaches the cladding soot layer should have a bulk density of at least 0.25g/cm3 ([0028]), which falls within the claimed range of 0.25 g/cm3 to 0.35g/cm3. Nakajima teaches a density of 0.25g/cm3 is required to ensure sufficient strength in the preform to prevent cracking in clad soot layer. Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided for a similar density for the soot formed in the forming the first clad and second clad, so as to ensure sufficient strength to prevent cracking, as taught by Nakajima.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Ishikawa et al. (5,895,515) as applied to claim 1 above, and further in view of Nakajima (2015/0040616). Ishikawa teaches the flow rate of silicon tetrafluoride is increased linearly from 50 SCCM to 100 SCCM as deposition of soot proceeds in the axial direction (col. 7 lines 34-35). Accordingly, at one point of deposition, the flow rate of silicon tetrafluoride is in the range of 56 SCCM to 62 SCCM, which is 1.6-1.8 times lower than the final flow rate of 100 SCCM. However, Ishikawa does not specify a density of the soot formed. Nakajima teaches a similar method for producing an optical fiber preform comprising forming a core and cladding soot layers by a vapor axial deposition process ([0020]). Nakajima further teaches the cladding soot layer should have a bulk density of at least 0.25g/cm3 ([0028]), which falls within the claimed range of 0.25 g/cm3 to 0.35g/cm3. Nakajima teaches a density of 0.25g/cm3 is required to ensure sufficient strength in the preform to prevent cracking in clad soot layer. Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided for a similar density for the soot formed in the forming the first clad and second clad, so as to ensure sufficient strength to prevent cracking, as taught by Nakajima.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Ishikawa et al. (5,895,515) as applied to claim 1 above, and further in view of Nakamura et al. (JP 2003261336 machine translation provided). Ishikawa discloses a concern for producing an optical fiber preform having an uniform refractive index difference in an axial direction of the preform (col. 2 lines 62-67). However, Ishikawa doesn’t specify heating the first and second clad such that sintering of the second clad proceeds more than sintering of the first clad. Nakamura also shares a similar concern of achieving a uniform refractive index difference in an axial direction of an optical fiber preform (abstract, [0002]). Nakamura recognizes upper portion of the preform experiences extra heating (pre-heating) more than the lower portion and in order to provide for more uniform heat energy to the preform in an axial direction, Nakamura teaches heating the end portion of the optical fiber preform in a dehydration and sintering step more than a center portion of the preform, such that sintering of the end portion proceeds more than sintering of the center portion (3rd paragraph on p. 2, 1st paragraph on p. 5, 2nd-4th paragraphs on p.7). Nakamura teaches this provides for adjustment to the refractive index difference at the end portion so that a variation in the refractive index difference along the axial direction of the preform is reduced (abstract). 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 step of heating the end portion (second clad) more than the central portion (first clad), such that sintering of the second clad proceeds more than sintering of the first clad, so as to provide for uninform heat energy in an axial direction of the preform, and thereby reducing a variation in the refractive index difference in the axial direction.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Ishikawa et al. (5,895,515) as applied to claim 1 above, and further in view of Hayashi (JP 2007063032 machine translation provided). Ishikawa teaches drawing the optical fiber preform to form a bare optical fiber (col. 8 lines 13-14). Although Ishikawa does not disclose coating a resin around the bare optical fiber, it is a well-known step in the manufacturing of optical fiber. For example, Hayashi teaches drawing a bare optical fiber from a preform and coating a resin around the bare optical fiber that is ultraviolet curable (bottom third of pa. 5). It would have been obvious to one of ordinary skill in the art at the time of the invention to have provided for a resin coating on the bare optical fiber, as it is readily curable, and provides protection to the bare optical fiber.
Conclusion
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.
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/QUEENIE S DEHGHAN/Primary Examiner, Art Unit 1741
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