DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on May 12, 2026 has been entered.
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 § 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, 4 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Filippov et al. (2011/0289980) in view of Bhandarkar et al. (JP 4215997 machine translation provided) and Guigné et al. (5,500,493). Filippov teaches a method for producing an optical fiber comprising drawing an optical fiber in a draw tower, and trapping the optical fiber along a vertical axis that is parallel with the draw tower axis (abstract, [0024], [0026], figure 1). Filippov teaches trapping the optical fiber along a vertical axis by arranging a non-contact centering device in the vicinity of the optical fiber. Filippov teaches the centering device centers the optical fiber in order to stabilize the fiber as it passes through the exit orifice of the treatment device and ensure the optical fiber does not contact the walls of the exit orifice 26 ([0026], [0035]). Filippov specifies the exit orifice has diameter in the range of 0.5 mm to 5mm ([0027]). Accordingly, Filippov teaches the movement of the optical fiber is constrained within 1 mm from the vertical axis, especially in the case where the orifice diameter is 1 mm or less ([0036]). Filippov teaches the centering device can be utilized in other locations within the optical fiber production system to center the optical fiber ([0037]). Filippov further teaches coating the optical fiber to generate a coated optical fiber ([0024]). As can be seen in figure 1, the optical fiber is subsequently passed through a coating unit 60 after being centered. Bhandarkar similarly teaches drawing an optical fiber in a furnace and coating the fiber as it is drawn (fig. 6). Bhandarkar teaches the fiber is coated by passing the fiber through a coating die and subsequently cured. Also, it would appear the coating thickness and coating geometry is determined by the coating die. Bhandarkar stresses the importance of passing the fiber through the center of the coating die to ensure concentricity between the fiber and the coating ([0036]). Accordingly, it would be obvious to one of ordinary skill in the art at the time of the invention to have utilized a centering device near the coating unit, so as to ensure centering of the fiber within the die for uniform coating. Since Filippov teaches the optical fiber is substantially centered ([0035]-[0036]), then it would be expected that the coated optical fiber would not have any coating ovality, or at the very least have a coating ovality of less than 4%, as Bhandarkar suggests a centered fiber within the coating die would provide for uniform coating thickness. Filippov teaches the centering device applies a forced fluid on the optical fiber to provide contactless centering. More specifically, Filippov teaches placing at least two centering device in opposing positions to apply opposing pressure on opposite sides of the fiber ([0032]) or using a tube to applying multiple opposing centering forces around the fiber ([0035]-[0036]). However, Filippov doesn’t specify using acoustic waves. Guigné teaches using acoustic energy to position objects by generating an acoustic radiation pressure by one or more acoustic waves near the object (col. 1 lines 5-17, 45-54, col. 6 lines 43-49, 57-61, 66-67, col. 7 lines 1-25) and exemplifies applying acoustic waves to a glass object (col. 4 lines 1-12). Guigné teaches applying acoustic waves to position this glass object provides for no contact with the glass, thereby preventing contamination of the glass, making it suitable for the production of optical fibers. Like Filippov, Guigné also teaches placing acoustic wave transducers in opposing positions to apply opposing pressures on the opposite sides of the glass object, so as to maintain a horizontal position of the glass object (col. 6 lines 55-61). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have tried acoustic waves as an alternative pressure means for centering the optical fiber of Filippov as Guigné teaches it is a well-known means that predictably provides for contactless positioning of glass objects with a reasonable expectation of success. Furthermore, Filippov teaches trapping the fiber for at least 3 mm vertical length of the optical fiber in the draw tower, such as 0.5cm to 2 cm ([0034]) or 25cm ([0036]), and with the application of acoustic waves, it would be reasonable to have similarly apply the acoustic waves so that the fiber is trapped for at least 3 mm vertical length of the optical fiber in the draw tower.
Regarding claim 4, Guigné further teaches it is known in the conventional art to use one or more acoustic standing waves patterns to provide acoustic pressure for positioning an object (col. 1 lines 1-28). Accordingly, it would have been obvious to one of ordinary skill in the art to have applied the well-known means for producing the acoustic pressure, such as acoustic standing waves, as taught by Guigné. Filippov teaches arranging a centering device on one side of the optical fiber, and a second one on an opposite side of the optical fiber (fig 2, [0033]). In applying the acoustic standing waves to in a similar arrangement, the centering device would provide a first acoustic wave in a first direction and a second wave in a second direction that is opposite to the first direction to generate a plurality of standing waves, wherein the plurality of standing waves generates acoustic radiation pressure for trapping the optical fiber in a central position along the vertical axis.
Regarding claim 6, Filippov teaches the optical fiber has a diameter of 125 µm ([0036]), which is less than 150µm.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Filippov et al. (2011/0289980) in view of Bhandarkar et al. (JP 4215997 machine translation provided) and Guigné et al. (5,500,493) as applied to claim 1 above, and further in view of Groh et al. (2020/0283329). Filippov teaches the optical fiber is drawn from a glass optical fiber preform ([0020], but doesn’t specify the material or density of the material. Groh teaches a method for producing an optical fiber preform for drawing into optical fiber ([0039]), the method comprising forming a porous preform and consolidating the preform into a transparent or vitrified glass body suitable for use in an optical fiber draw process ([0043]). Groh further teaches the transparent consolidated preform consists of silica or doped silica with a bulk density in the range of 2.05-2.20 g/cm3 ([0043]), which overlaps with the claimed range of 2.19-2.20 g/cc. 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 density of 2.05-2.20 g/cm3, or even 2.19-2.20g/cc, for the optical fiber preform of Filippov as Groh teaches they provide for suitable optical fiber preforms for drawing into optical fiber with predictable success.
Response to Arguments
Applicant's arguments filed December 19, 2025 have been fully considered but they are not persuasive. 1. Physical incompatibility and negative teaching. Applicant argues the fluid based systems involves turbulence and mass transports which can introduce fluctuations and contaminants to the optical fiber, in contrast to the acoustic radiation pressure of the claimed invention. It would appear the applicant is providing for motivation for replacing the fluid based centering device of Filippov, which is in line with the rejection, which suggests using acoustic radiation instead, as suggested by Guigné.
Applicant argues one of ordinary skill would not simply swap fluid nozzles for acoustic transducers because their mode of operations are governed by different principles, thereby requiring a complete redesign of the treatment device of Filippov. “The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference,” In re Keller, 642 F.2d 413, 425 (CCPA 1981). “Rather, the test in what the combined teachings of the references would have suggested to those of ordinary skill in the art.” Id. Both Filippov and Guigné solves the same problem of how to center an object by applying pressure in non-contact manner. Accordingly, it would be obvious to one of ordinary skill to seek out other mean for centering the optical fiber in a non-contact manner. It is not clear why the substitution of the centering device of Filippov would require a redesign of the treatment device and exit orifice, as the centering device is separate and located downstream of the treatment device, and can be used in other locations, such as near the coating device.
2. Criticality of the 3mm Vertical Length and 4% Ovality. Applicant argues specific vertical length of acoustic trapping is required to achieve coating symmetry. This argument is not sufficient evidence for criticality of the 3mm vertical length. Nonetheless, Filippov clearly teaches applying the centering force for a distance of 0.5cm to 2 cm in one embodiment ([0034]) or 25cm in another embodiment ([0036]). Both of which are clearly larger than 3mm.
Applicant further elaborates on the centering device of Filippov, which uses high-pressure fluid to provide a centering force, which can have impurities and Guigné teaches levitating a large diameter object against gravity and fails to teaches the claimed method. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). It is the combination of Filippov and Guigné that teaches the claimed method. More specifically, the rejection did not insist on using the high pressure fluid centering device of Filippov, but instead, modifying the centering device with other known options, such as the acoustic radiation of Guigné, which is very much in line with the applicant’s argument for using other sources of pressure for centering. Furthermore, while Guigné doesn’t disclose the claimed method, Guigné is used to modify Filippov, and Filippov teaches the claimed method.
Furthermore, applicant argues the acoustic beam of Guigné cannot be applied to a small diameter optical fiber, but fails to point to evidence to support the argument. While Guigné exemplifies using large acoustic forces for positioning a large diameter glass sphere, Guigné teaches positioning objects using acoustic waves is traditionally performed on much smaller objects (see background). Also, one skilled in the art would take from Guigné the technique of using acoustic waves to position glass optical fiber, and not the same exact acoustic levitation apparatus of Guigné. Thus, one skilled in the art would apply the appropriate acoustic radiation pressure on the optical fiber.
Applicant further argues the narrow range of density is at the very edge of Groh’s disclosure. In response, Groh, nonetheless discloses a density that satisfies the claimed range of density. Applicant notes the effectiveness of the trap is dependent on the relationship between the glass density and the acoustic medium. In response, one skilled in the art would be skilled to make the necessary determination for appropriating the necessary acoustic medium and force needed for centering the optical fiber. Again, the obviousness lies in what was suggested by Guigné, and not the actual bodily incorporation of the actual acoustic device of Guigné in to Filippov.
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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