Gerd Bechtel et al.

Patent Trials and Appeals Board

Sep 20, 2019

13980451 - (D) (P.T.A.B. Sep. 20, 2019)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
13/980,451 07/18/2013 Gerd Bechtel BECH3006/JS-FD 2976
23364 7590 09/20/2019
BACON & THOMAS, PLLC
625 SLATERS LANE
FOURTH FLOOR
ALEXANDRIA, VA 22314-1176
EXAMINER
PHAN, TRUONG D
ART UNIT PAPER NUMBER
2861
NOTIFICATION DATE DELIVERY MODE
09/20/2019 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
MAIL@BACONTHOMAS.COM
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte GERD BECHTEL, ARMIN WERNET, and
KAJ UPPENKAMP
____________

Appeal 2018-009108
Application 13/980,451
Technology Center 2800
____________

Before MICHELLE N. ANKENBRAND, Acting Vice Chief Administrative
Patent Judge, DONNA M. PRAISS, and JEFFREY R. SNAY,
Administrative Patent Judges.

PRAISS, Administrative Patent Judge.

DECISION ON APPEAL1
Appellant2 appeals under 35 U.S.C. § 134(a) from the Examiner’s
decision rejecting claims 12–17 and 19–22.3 We have jurisdiction over the
appeal under 35 U.S.C. § 6(b). We AFFIRM.

1 Our Decision refers to the Specification (“Spec.”) filed July 18, 2013, the
Examiner’s Final Office Action (“Final Act.”) dated Aug. 15, 2017,
Appellant’s Appeal Brief (“Appeal Br.”) filed Feb. 15, 2018 as corrected
Apr. 2, 2018, the Examiner’s Answer (“Ans.”) dated July 26, 2018, and
Appellant’s Reply Brief (“Reply Br.”) dated Sept. 26, 2018.
2 Appellant identifies “Endress + Hauser GMBH + Co. KG” as the real party
in interest. Appeal Br. 2.
3 The Examiner indicates that dependent claim 18 would be allowable if
rewritten in independent form. Final Act. 20.
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STATEMENT OF THE CASE
The invention “relates to apparatus and method for capacitive
determining and/or monitoring at least of the fill level of a medium in a
container using a probe unit.” Spec. 1:4–6. According to the Specification,
measuring devices for determining the fill level of liquid media ascertain the
capacitance that a probe electrode and a container wall or a second electrode
form. Id. at 1:10–16. The Specification explains that a measuring frequency
can be used that is suitable for all probe lengths, however, such a frequency
is not optimal for shorter probes because the smaller the frequency, the
longer the probe electrode must be. Id. at 1:26–33. The Specification also
states that when a medium has a conductivity value lying in a transitional
region between a permittivity dependent and a permittivity independent
measuring range, a fill level cannot be determined reliably via capacitive fill
level measurement. Id. at 2:1–5.
The stated object of the invention, therefore, is to provide a probe
electrode with a frequency sweep for an electrical, transmitted signal that
ascertains a measuring frequency optimal for the application parameters,
thereby obviating the need for a user to choose between measurement
frequencies as a function of a respective application. Id. at 2:10–19, 3:16–
19. According to the Specification, the electronics unit determines an
optimal measuring frequency based on the frequency sweep and determines
fill level from the response signal belonging to the optimal measuring
frequency. Id. at 2:18–21.
Claim 12, reproduced below from the Claims Appendix to the
corrected Appeal Brief filed April 2, 2018, is illustrative of the subject
matter on appeal (emphases added).
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12. An apparatus for capacitive determining and/or
monitoring at least a fill level of a medium in a container,
comprising:
a probe unit having at least one probe electrode; and
an electronics unit, which supplies at least said probe
electrode with an electrical, transmitted signal, and receives and
evaluates an electrical, response signal from said at least one
probe unit, wherein:
said electronics unit supplies said at least one probe
electrode at least at times by means of a frequency sweep with a
transmitted signal, which has a plurality of discrete exciter
frequencies following one another within a predeterminable
frequency band, wherein present application parameters
establish an optimal measuring frequency within said frequency
band, in case of which the fill level is determinable most
accurately,
said electronics unit, based on the frequency sweep,
ascertains from the response signal characterized by the present
application parameters said optimal measuring frequency
optimal for the present application parameters, and
said electronics unit determines the fill level from the
response signal belonging to the optimal measuring frequency.
Independent claim 13 recites “[a] method for capacitive determining and/or
monitoring at least a fill level of a medium in a container with a probe unit
having at least one probe electrode” comprising, among other things,
supplying a probe electrode, by means of a frequency sweep, with an
electrical, transmitted signal; based on the frequency sweep, ascertaining an
optimal measuring frequency; and determining the fill level from a response
signal belonging to the optimal measuring frequency.

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ANALYSIS
We review the appealed rejections for error based upon the issues
Appellant identifies and in light of the arguments and evidence produced
thereon. Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010) (precedential)
(cited with approval in In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011)
(“[I]t has long been the Board’s practice to require an applicant to identify
the alleged error in the examiner’s rejections.”)). After considering the
argued claims in light of the case law presented in this Appeal and each of
Appellant’s arguments, we are not persuaded of reversible error in the
Examiner’s rejections.

Rejection 1: Obviousness over Wernet and Erazo
The Examiner rejects claims 12–17, 21 and 22 under 35 U.S.C.
§ 103(a) as unpatentable over Wernet4 and Erazo5 for the reasons provided
on pages 9–17 of the Final Office Action.
Appellant argues the claims together. Appeal Br. 16–18. Therefore,
we confine our discussion to claim 12, which we select as representative.
Claims 13–17, 21, and 22 stand or fall with claim 12. See 37 C.F.R.
§ 41.37(c)(1)(iv).
The Examiner finds Wernet discloses an apparatus for capacitive
determining and/or monitoring at least a fill level of a medium in a container
that includes, among other things, a probe unit and an electronics unit. Final
Act. 9–10. The Examiner finds Wernet does not explicitly disclose that the
electronics unit supplies the probe with a transmitted signal by means of a

4 Wernet et al., US 2010/0141285 A1, published June 10, 2010 (“Wernet”).
5 Erazo, US 2008/0060432 A1, published Mar. 13, 2008.
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frequency sweep, wherein present application parameters establish an
optimal measuring frequency and the electronics unit, based on the
frequency sweep, and the electronics unit ascertains an optimal measuring
frequency for the present application parameters and determines the fill
level, as claim 12 requires. Id. at 10.
The Examiner finds Erazo discloses determining the level of a
material in a vessel by coupling a probe to the vessel, using a variable
frequency controller to apply a periodic signal to the probe at discrete
frequencies within a range, and selecting an operating frequency. Id. at 11.
The Examiner concludes it would have been obvious to modify Wernet in
view of Erazo to optimize the sensitivity of the probe to changes in material
level and to provide an apparatus that is adapted to be calibrated. Id. at 12.
Appellant asserts that Wernet is concerned with an apparatus having
at least two electrodes, whereas Appellant’s invention does not necessitate
two electrodes. Appeal Br. 16–17. Appellant argues Wernet does not
disclose or suggest a frequency sweep or an evaluation for determining an
optimal frequency from a frequency sweep. Id. at 17–18; Reply Br. 2.
Appellant contends Erazo uses a fixed frequency during normal
operation and “[o]nly for calibration purpose, the frequency is varied to
optimize sensitivity at the probe.” Appeal Br. 17; Reply Br. 2. Appellant
asserts that Erazo’s calibration is carried out with a reference impedance that
“is not present in the present application.” Appeal Br. 17–18; Reply Br. 2.
Appellant’s arguments do not persuade us that the Examiner
reversibly erred in rejecting the claims over the cited prior art references.
Accordingly, we sustain the Examiner’s rejection for essentially those
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reasons expressed in the Answer, including the Response to Argument
section, and we add the following primarily for emphasis.
As the Examiner’s Answer indicates, Appellant’s argument that its
apparatus does not require two electrodes fails from the outset because it is
not based on limitations set forth in the claim. Ans. 5–6; see In re Self, 671
F.2d 1344, 1348 (CCPA 1982). Claim 12 does not limit the claimed
invention to a single electrode, but, rather, recites “a probe unit having at
least one probe electrode,” which permits multiple probe electrodes. This is
consistent with the Specification’s broader disclosure of “at least one probe
electrode.” Spec. 2:10–12. Although we interpret claims in light of the
Specification, to the extent the Specification discloses an embodiment
limited to a single electrode, we do not read those limitations into the claims.
See In re Van Geuns, 988 F.2d 1181, 1184 (Fed. Cir. 1993).
Appellant’s other arguments concerning Wernet are also unpersuasive
because they do not address what the combination of the applied references
would have suggested to one of ordinary skill in the art. In re McLaughlin,
443 F.2d 1392, 1395 (CCPA 1971) (“[T]he test for combining references is
not what the individual references themselves suggest but rather what the
combination of disclosures taken as a whole would suggest to one of
ordinary skill in the art.”).
Wernet discloses an apparatus for determining and/or monitoring at
least one process variable, such as the fill level of a medium. Wernet ¶ 1.
Wernet discloses a measuring device for determining the fill level of a
medium (e.g., a liquid) in a container. Id. ¶ 21. Wernet’s measuring device
includes an electronics unit and a probe unit having an inner electrode and
outer electrodes. Id. ¶¶ 21, 24. The inner and outer electrodes can be
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supplied with exciter signals in different sequences. Id. ¶ 24. To the extent
Wernet does not explicitly disclose the claimed frequency sweep, Wernet
nevertheless teaches sending different, varying frequencies to its probe unit
in either continuous or discrete steps. Id.
Erazo relates to the indication of material level in a vessel as a
function of the capacitance of the material within the vessel. Erazo ¶ 1.
Erazo discloses a system that includes, among other things, a probe, a driver
amplifier coupled to the probe for applying a periodic electrical signal, and a
variable frequency generator for controlling the frequency of the signal. Id.
¶ 7. Erazo discloses a calibration mode in which the variable frequency
controller applies a periodic electrical signal to the probe at discrete
frequencies within a frequency range. Id. ¶¶ 10, 11. Admittance at the
probe is measured both with and without a reference impedance in parallel
with the probe and the admittance return signal is monitored to determine
the operating frequency at which an admittance difference between the
measurements is greatest. Id. ¶¶ 11, 12.
Erazo teaches that the calibration mode may be carried out to optimize
sensitivity of the probe by identifying the frequency at which the probe is
most sensitive to a change in capacitance at the probe. Id. ¶ 5. A fixed
frequency used during a measurement mode of operation for determining the
level of a material is set as the frequency identified by the calibration mode
of operation. Id. ¶¶ 5, 9.
Erazo’s disclosure supports the Examiner’s finding that Erazo
discloses an electronics unit that supplies a probe electrode with a
transmitted signal by means of a frequency sweep, as claim 12 recites. Final
Act. 11; Ans. 4–5. Erazo’s disclosure also supports the Examiner’s finding
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that the prior art discloses an electronics unit that ascertains an optimal
measuring frequency based on a frequency sweep, as claim 12 requires.
Erazo ¶¶ 5, 12. As a result, Appellant’s arguments that Wernet alone does
not disclose or suggest a frequency sweep or an evaluation to ascertain an
optimal frequency from a frequency sweep are unpersuasive because the
teachings of Wernet and Erazo, taken as a whole, would have suggested
these limitations of claim 12. Further, Appellant’s argument regarding
Erazo’s use of a reference impedance is unpersuasive because claim 12 does
not exclude a reference impedance.
As discussed above, Appellant contends that Erazo only varies the
frequency during the calibration operation, not during normal operation.
Appeal Br. 17–18; Reply Br. 2. Claim 12, however, encompasses the
calibration mode of operation and the measurement mode of operation Erazo
discloses. More specifically, an electronics unit supplying at least one probe
electrode with a transmitted signal by means of a frequency sweep and
ascertaining an optimal measuring frequency from a response signal, as
claim 12 recites, reads upon the calibration mode of operation Erazo
discloses. Claim 12’s electronics unit that determines a fill level from a
response signal belonging to an optimal measuring frequency therefore reads
upon Erazo’s electronics unit, which uses the frequency identified during the
calibration mode of operation in a measurement mode of operation.6

Appellant also contends that one of ordinary skill in the art would not
have modified Wernet in view of Erazo to arrive at the claimed invention

6 Claim 13’s method similarly reads upon Erazo’s calibration and
measurement modes of operation.
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because there would have been no motivation or suggestion to change
Wernet’s fixed frequency to a frequency sweep. Reply Br. 3. According to
Appellant, “[a]ny such modification might, at best, result in a calibration
mode just like Erazo’s that is separate and apart from a normal
‘measurement mode of operation” and the Examiner’s asserted motivation
“can only lead to addition of Erazo’s calibration mode.” Id.
This argument was not presented in the Appeal Brief, and Appellant
has not proffered a showing of good cause explaining why the argument
could not have been presented in the Appeal Brief. Therefore, we will not
consider this new and untimely argument in our assessment of the
Examiner's rejections. 37 C.F.R. § 41.41(b)(2) (2014). Even if we were to
consider Appellant’s new argument, we do not find it persuasive of error.
As noted above, the Examiner provided a reason that a person of ordinary
skill in the art would have modified Wernet with the teachings of Erazo,
namely, to optimize the probe’s sensitivity to changes in material level and
provide an apparatus that is adapted to be calibrated. Final Act. 12. The
record on appeal supports the Examiner’s reasoning. Erazo ¶ 5.
In addition, Appellant’s description of the combination resulting in
Erazo’s calibration mode of operation as a separate operation from a
measurement mode of operation in Wernet’s apparatus (Reply Br. 3) is
consistent with the Examiner’s stated reason that the combination would
adapt the apparatus for calibration using Erazo’s method (Final Act. 12). In
other words, one of ordinary skill in the art would have performed Erazo’s
calibration mode to identify an operating frequency, as Erazo teaches, and
would have used the identified frequency as Wernet’s fixed frequency to
determine the fill level of medium, much like Erazo does. See Wernet ¶¶ 1,
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24; Erazo ¶¶ 3, 5. As discussed above, the claimed invention reads on the
combination of Wernet and Erazo because the independent claims
encompass an apparatus and method comprising a calibration mode of
operation and a measurement mode of operation as the disclosures of Wernet
and Erazo teach. Id.
For these reasons, and those the Examiner provides, we uphold the
Examiner’s rejection of claims 12–17, 21, and 22 under 35 U.S.C. § 103(a)
as obvious over Wernet and Erazo.

Rejections 2 and 3: Obviousness over Wernet, Erazo,
and Additional References
The Examiner rejects claim 19 under 35 U.S.C. § 103(a) as
unpatentable over Wernet and Erazo and further in view of Lundstrom7 for
the reasons provided on pages 17–19 of the Final Office Action.
The Examiner rejects claim 20 under 35 U.S.C. § 103(a) as
unpatentable over Wernet and Erazo and further in view of Zimmermann8
for the reasons provided on pages 19–20 of the Final Office Action.
Appellant does not present separate arguments for the rejections of
claims 19 and 20. Appeal Br. 18. Therefore, for the reasons discussed
above, and those the Examiner provides, we uphold the Examiner’s
rejections of claims 19 and 20 under 35 U.S.C. § 103(a).

7 Lundstrom, US 2008/0295569 A1, published Dec. 4, 2008.
8 Zimmermann et al., EP 2 128 587 A1, published Feb. 12, 2009.
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DECISION
Upon consideration of the record, and for the reasons given above, in
the Final Office Action, and in the Examiner’s Answer, the decision of the
Examiner rejecting claims 12–17 and 19–22 under 35 U.S.C. § 103(a) is
affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1).

AFFIRMED