DETAILED ACTION
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 .
Response to Arguments
Applicant's arguments filed 01/11/2026 have been fully considered but they are not persuasive.
Examiner disagrees that Chan “teaches away from using a multi-mode fiber with a NA of 0.2 or less when other alternatives with higher NA are widely available”. The examiner notes that in [0042] Chan discloses adding a collimating lens to the tip of the POF in order to measure a specific location on the fuel surface. This achieves the same effect as using a smaller NA fiber, which therefore negates applicant’s argument that high NA fibers are required by Chan.
Examiner asserts that the existing rejection relying on Jensen provides sufficient motivation to combine the teaching of Di with the device of Chan. Jensen discloses that a multimodal fiber with a numerical aperture of 0.12 can allow for efficient coupling into affordable and powerful diodes using only a simple optical system. Simple optical systems have clear benefits for the user both in terms of reduced space usage and lower component costs.
The examiner notes that Chan, Di, and Jones are all in the same field of endeavor of distance detection.
Claim Rejections - 35 USC § 103
Claims 1-3, 10, 13-15, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Chan (US 2020/0326224A1) in view of Di (CN 106772312 A) and further in view of Mansell (US 2013/0265583).
Regarding Claim 1, Chan discloses a proximity sensor (Abstract: “A fuel level calculator calculates the fuel level based on the time interval provided by the time delay detection circuit.”), comprising:
a light source configured to emit a beam of optical radiation (Figure 1, element 28; [0032]: “a high-peak-power laser device 28”);
a detector configured to output an electrical signal in response to the optical radiation that is incident on the detector (Figure 1, element 32; “a photodetector 32, which is used for detection of the return laser pulse 20 (which may consist of one or more photons) reflected from the fuel surface 3 and the end face of POF 14. The return laser pulse 20 is guided by POFs 14 and 24 back to the photodetector 32. In accordance with one proposed implementation, the photodetector 32 is a high-sensitivity photon-counting avalanche photodiode.”);
a first optical fiber configured to receive the emitted beam and to direct the emitted beam toward an object (Figure 1, element 22; [0034]: “The emitted light pulses 18 propagate through POF 22”) ;
a second optical fiber configured to receive the optical radiation reflected from the object and to convey the received optical radiation to the detector (Figure 1, element 24; [0035]: “The weak laser return pulse 20 received by POF 14 at the end face 1 (see FIG. 2) will propagate back to the photodetector 32 by way of the lx2 optical fiber coupler 16 and POF 24.”); and
a processor coupled to process the electrical signal so as to compute a distance to the object ([0037]: “The FQODC 36 includes a computer or processor configured to process sensor data (including fuel level data received from the fuel level calculator 34 and other data as described below with reference to FIG. 4) and a nontransitory tangible computer-readable”).
Chan does not teach and Di does teach that the fibers are multimode fibers ([0059]: “The first optical fiber 1 and the second optical fiber 2 are ordinary optical fibers, such as multimode optical fibers with a core diameter of 200μm and a numerical aperture of 0.12 produced by Shanghai Hanyu Company.”).
Chan does not teach and Di does teach wherein a numerical aperture (NA) of each of the first and second optical multimode fibers does not exceed 0.2 ([0059]: “The first optical fiber 1 and the second optical fiber 2 are ordinary optical fibers, such as multimode optical fibers with a core diameter of 200μm and a numerical aperture of 0.12 produced by Shanghai Hanyu Company.”)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the level sensor of Chan with the teaching of Di to use multimode optical fibers with a numerical aperture of 0.12 for transmitting and receiving optical signals. Jensen (US 2010/0208318 A1) notes in [0013] that “A multimodal fibre having … a numerical aperture of, for example, 0.12 is suitable for this purpose.” Jensen further notes that “An economical and powerful broad-area diode laser can be efficiently coupled into such a fibre via a simple transmission optical system.” It follows as well due to the reversibility of light through optical components that the input light from the observed scene could also be coupled into that fiber with a simple transmission optical system.
Chan in view of Di does not teach and Mansell does teach wherein the distance does not exceed 100 cm ([0036]: “Then, assuming that the maximum travel distance for object 28 1s 60 cm, a 1 mm position change for the object will correspond to a change in the modulator frequency of about 1.7 kHz, which should be relatively easy to detect.”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the liquid level sensor of Chan in view of Di with the teaching of Mansell to have the maximum distance measured by the device be less than 100 cm. One of ordinary skill in the art at the time of filing would be aware of proximity sensors designed and optimized for very short range use, e.g., those used to deactivate touch screens during calls made from mobile devices.
Regarding Claim 2, which depends from rejected Claim 1, Chan further teaches wherein the light source is configured to output pulses of the optical radiation (Figure 1, element 26; [0032]: “The laser device 28 is connected to a laser driver 26 with a high-speed pulse generator.” And “The laser device 28 is controlled by the laser driver 26 to emit a laser pulse 18 having a width of about 0.1 nsec or less.”), and the electrical signal output by the detector is indicative of a time of flight of the optical pulses ([0036]: “In response to detection of the reflected optical pulses, the photodiode 32 outputs narrow electrical pulses with pulse width of 100 psec or less to a time delay detection circuit 30. The time delay detection circuit 30 determines the difference (ΔTD) between the time of arrival of the pulse reflected by the end face 1 and the time of arrival of the pulse reflected by the fuel surface 3.”), and the processor is configured to compute the distance to the object based on the time of flight ([0036]: “The difference (ΔTD) is equal to the time-of-flight of a photon that propagates from the end face 1 to the fuel surface 3 and then back to the end face 1, each leg of the optical path being equal to a distance D (shown in FIG. 1). Since the speed of light is known, the distance D can be calculated from the difference (ΔTD)·)
Regarding Claim 3, which depends from rejected Claim 1, Chan further teaches wherein the first and second optical multimode fibers comprise plastic optical fibers (Abstract: “A fuel sensing system utilizes non-contact plastic optical fiber (POF) to optically sense the level of liquid fuel in a fuel tank.”).
Regarding Claim 10, which depends from rejected Claim 1, Chan further teaches wherein at least one of the first and second optical multimode fibers is bent so as to deviate from a straight line (Figure 1, elements 22 and 24 are both shown to have bends).
Regarding Claim 13, Chan discloses a method for proximity sensing (Abstract: “A fuel level calculator calculates the fuel level based on the time interval provided by the time delay detection circuit.”), comprising:
directing a beam of optical radiation from a light source (Figure 1, element 28; [0032]: “a high-peak-power laser device 28”) through a first optical fiber toward an object (Figure 1, element 22; [0034]: “The emitted light pulses 18 propagate through POF 22”);
receiving the optical radiation reflected from the object in a second optical fiber and conveying the received optical radiation through the second optical fiber to a detector (Figure 1, element 24; [0035]: “The weak laser return pulse 20 received by POF 14 at the end face 1 (see FIG. 2) will propagate back to the photodetector 32 by way of the lx2 optical fiber coupler 16 and POF 24.”); and
processing an electrical signal output by the detector in response to the received optical radiation ([0036]: “In response to detection of the reflected optical pulses, the photodiode 32 outputs narrow electrical pulses with pulse width of 100 psec or less to a time delay detection circuit 30. The time delay detection circuit 30 determines the difference (ΔTD) between the time of arrival of the pulse reflected by the end face 1 and the time of arrival of the pulse reflected by the fuel surface 3.”) so as to compute a distance to the object ([0037]: “The FQODC 36 includes a computer or processor configured to process sensor data (including fuel level data received from the fuel level calculator 34 and other data as described below with reference to FIG. 4) and a nontransitory tangible computer-readable”).
Chan does not teach and Di does teach that the fibers are multimode fibers ([0059]: “The first optical fiber 1 and the second optical fiber 2 are ordinary optical fibers, such as multimode optical fibers with a core diameter of 200μm and a numerical aperture of 0.12 produced by Shanghai Hanyu Company.”).
Chan does not teach and Di does teach wherein a numerical aperture (NA) of each of the first and second optical multimode fibers does not exceed 0.2 ([0059]: “The first optical fiber 1 and the second optical fiber 2 are ordinary optical fibers, such as multimode optical fibers with a core diameter of 200μm and a numerical aperture of 0.12 produced by Shanghai Hanyu Company.”)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the level sensor of Chan with the teaching of Di to use multimode optical fibers with a numerical aperture of 0.12 for transmitting and receiving optical signals. Jensen (US 2010/0208318 A1) notes in [0013] that “A multimodal fibre having … a numerical aperture of, for example, 0.12 is suitable for this purpose.” Jensen further notes that “An economical and powerful broad-area diode laser can be efficiently coupled into such a fibre via a simple transmission optical system.” It follows as well due to the reversibility of light through optical components that the input light from the observed scene could also be coupled into that fiber with a simple transmission optical system.
Chan in view of Di does not teach and Mansell does teach wherein the distance does not exceed 100 cm ([0036]: “Then, assuming that the maximum travel distance for object 28 1s 60 cm, a 1 mm position change for the object will correspond to a change in the modulator frequency of about 1.7 kHz, which should be relatively easy to detect.”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the liquid level sensor of Chan in view of Di with the teaching of Mansell to have the maximum distance measured by the device be less than 100 cm. One of ordinary skill in the art at the time of filing would be aware of proximity sensors designed and optimized for very short range use, e.g., those used to deactivate touch screens during calls made from mobile devices.
Regarding Claim 14, which depends from rejected Claim 13, Chan further teaches wherein directing the beam of optical radiation comprises directing a beam of pulses of the optical radiation (Figure 1, element 26; [0032]: “The laser device 28 is connected to a laser driver 26 with a high-speed pulse generator.” And “The laser device 28 is controlled by the laser driver 26 to emit a laser pulse 18 having a width of about 0.1 nsec or less.”), and wherein processing the electrical signal comprises processing the electrical signal to compute the distance to the object based on a time of flight of the pulses ([0036]: “The difference (ΔTD) is equal to the time-of-flight of a photon that propagates from the end face 1 to the fuel surface 3 and then back to the end face 1, each leg of the optical path being equal to a distance D (shown in FIG. 1). Since the speed of light is known, the distance D can be calculated from the difference (ΔTD).
Regarding Claim 15, which depends from rejected Claim 13, Chan further teaches wherein the first and second optical multimode fibers comprise plastic optical fibers (Abstract: “A fuel sensing system utilizes non-contact plastic optical fiber (POF) to optically sense the level of liquid fuel in a fuel tank.”).
Regarding Claim 19, which depends from rejected Claim 13, Chan further teaches bending at least one of the first and second optical multimode fibers so as to deviate the at least one of the first and second optical multimode fibers from a straight line (Figure 1, elements 22 and 24 are both shown to have bends).
Claims 4, 5, 10, 17, and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Chan in view of Di and further in view of Mansell and further in view of Ishigure et al (https://ieeexplore.ieee.org/abstract/document/4137593).
Regarding Claim 4, which depends from rejected Claim 3, Chan in view of Di does not teach, but Ishigure does teach the plastic optical fibers comprise a core comprising a polymethylmethacrylate (PMMA) (Figure 1, panel c, the core material is composed of PMMA and a dopant), and at least one cladding material consisting of PMMA (Figure 1, panel b, PMMA homopolymer).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the fluid level sensor of Chan in view of Di with the teaching of Ishigure to use PVDF-clad plastic optical fibers. Ishigure notes in Page 1, Column 2, Paragraph 2 that PVDF-clad GI POFs exhibit both high mechanical-strength and very low bending loss, which are not achieved by conventional PMMA clad GI POF. Low bending loss in particular is beneficial in compact sensors where space constraints may necessitate bends in the optical fibers.
Regarding Claim 5, which depends from rejected Claim 4, Chan in view of Di does not teach and Ishigure does teach wherein the core comprises PMMA (Figure 1, panel c, core region is composed of PMMA and a dopant), and wherein the at least one cladding comprises a first cladding comprising PVDF (Figure 1, panel a, cladding comprises a PVDF-PMMA polymer blend) and a second cladding comprising PMMA (Figure 1, panel b, cladding comprises a PMMA homopolymer).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the fluid level sensor of Chan in view of Di with the teaching of Ishigure to use PVDF-clad plastic optical fibers. Ishigure notes in Page 1, Column 2, Paragraph 2 that PVDF-clad GI POFs exhibit both high mechanical-strength and very low bending loss, which are not achieved by conventional PMMA clad GI POF. Low bending loss in particular is beneficial in compact sensors where space constraints may necessitate bends in the optical fibers.
Claims 11 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Chan in view of Di and further in view of Mansell and further in view of Babin (US 7635854 B1).
Regarding Claim 11, which depends from rejected Claim 1, Chan in view of Di does not teach and Babin does teach wherein the first optical multimode fiber is configured to direct the beam of the optical radiation toward the object through a cover glass, and the second optical multimode fiber is configured to receive the optical radiation reflected from the object through the cover glass (Figure 3, element 260 is a protective optical window through which light is emitted and received).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the optical sensor of Chan in view of Di with the teaching of Babin to use an optical window in front of the receiving and emitting fibers. Babin notes in Column 11, Lines 16-19 that “A protective optical window 260 can be mounted in front of both lenses 220 and 230 to provide, for example, hermetical sealing of the housing 250.” Hermetically sealing potentially sensitive optical components like optical fibers away from dirty or high-touch environments is advantageous in that it protects them, and provides a much easier surface for the user or technician to clean.
Regarding Claim 20, which depends from rejected Claim 13, Chan in view of Di does not teach and Babin does teach wherein directing the beam of optical radiation toward the object comprises directing the beam from the first optical multimode fiber through a cover glass, and wherein receiving the optical radiation reflected from the object comprises receiving the radiation through the cover glass into the second optical multimode fiber (Figure 3, element 260 is a protective optical window through which light is emitted and received).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the optical sensor of Chan in view of Di with the teaching of Babin to use an optical window in front of the receiving and emitting fibers. Babin notes in Column 11, Lines 16-19 that “A protective optical window 260 can be mounted in front of both lenses 220 and 230 to provide, for example, hermetical sealing of the housing 250.” Hermetically sealing potentially sensitive optical components like optical fibers away from dirty or high-touch environments is advantageous in that it protects them, and provides a much easier surface for the user or technician to clean.
Claims 6, 7, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Chan in view of Di and further in view of Mansell and further in view of Thorlabs Multimode Round Fiber Optic Bundle Cables (https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=5609).
Regarding Claims 6 and 7, Chan in view of Di does not teach and Thorlabs does teach wherein each of the first and second optical multimode fibers comprises a respective plurality of multimode sub-fibers (Thorlabs p/n FG200LCC (the ‘sub-fiber’) is a 200 micron multimode fiber. The bundle cable BF13LSMA is composed of 19 of these fibers) and wherein each sub-fiber comprises a core and at least one cladding (The attached mechanical drawing for BF13LSMA shows that each FG200LCC sub-fiber in the cable comprises a core and at least on cladding).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute a multimode, multicore bundle of fibers in place of the multimode fibers taught in Chan in view of Di. Such components were well-known in the art, and commercially available at the time of filing, and their substitution would cause predictable results, especially given the fact that the salient characteristic of the fibers regarding the operation of the proximity sensor in the instant application is that they are multimode.
Regarding Claim 16, which depends from rejected Claim 13, Chan in view of Di does not teach and Thorlabs does teach wherein each of the first and second optical multimode fibers comprises a respective plurality of multimode sub-fibers (Thorlabs p/n FG200LCC (the ‘sub-fiber’) is a 200 micron multimode fiber. The bundle cable BF13LSMA is composed of 19 of these fibers; The attached mechanical drawing for BF13LSMA shows that each FG200LCC sub-fiber in the cable comprises a core and at least on cladding).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute a multimode, multicore bundle of fibers in place of the multimode fibers taught in Chan in view of Di. Such components were well-known in the art, and commercially available at the time of filing, and their substitution would cause predictable results, especially given the fact that the salient characteristic of the fibers regarding the operation of the proximity sensor in the instant application is that they are multimode.
Conclusion
THIS ACTION IS MADE FINAL. 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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/B.W.C./ Examiner, Art Unit 3645
/ISAM A ALSOMIRI/ Supervisory Patent Examiner, Art Unit 3645
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