Ex parte Glabe

Board of Patent Appeals and Interferences

Jan 30, 2001

08362747 (B.P.A.I. Jan. 30, 2001)

The opinion in support of the decision being entered today was not
written for publication and is not binding
Precedent of the Board.
Paper No. 34
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte KLAUS GLABE
____________
Appeal No. 1998-2867
Application No. 08/362,747
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HEARD: January 9, 2001
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Before THOMAS, GROSS, and BARRY, Administrative Patent Judges.
GROSS, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the examiner's final
rejection of claims 81 through 85, 89, 97, and 101. Claims 86
through 88, 90 through 92, 94 through 96, and 98 through 100
have been objected to as being dependent upon rejected base
claims.
Appellant's invention relates to a sensor-fault detection
circuit and method. Claim 97 is illustrative of the claimed
invention, and it reads as follows:
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97. A method for detecting faults in a sensor,
comprising
generating a test signal,
simultaneously transmitting said test signal to an input
of said sensor and to a first input of a time measuring
device,
outputting said test signal from an output of said
sensor, after it has been delayed by passing through said
sensor, to a second input of said time measuring device, and
determining a time difference between said delayed test
signal at said second input and said test signal at said first
input, and issuing an error signal if said time difference is
not within a predetermined range.
The prior art references of record relied upon by the
examiner in rejecting the appealed claims are:
Leiber et al. (Leiber) 4,085,979 Apr. 25,
1978
Bleckmann et al. (Bleckmann) 4,546,437 Oct.
08, 1985
Buchschmid et al. (Buchschmid) 4,652,818 Mar. 24,
1987
Claims 81 through 85, 89, 97, and 101 stand rejected
under 35 U.S.C. § 103 as being unpatentable. The examiner
applies Leiber alone against claims 81 through 83, 97, and
101, Leiber in view of Bleckmann against claims 84 and 89, and
Leiber in view of Buchschmid against claim 85.
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Reference is made to the Examiner's Answer (Paper No. 29,
mailed August 19, 1997) for the examiner's complete reasoning
in support of the rejections, and to appellant's Brief (Paper
Nos. 25 and 28, filed April 14, 1997 and July 14, 1997,
respectively) and Reply Brief (Paper No. 30, filed September
25, 1997) for appellant's arguments thereagainst.
OPINION
We have carefully considered the claims, the applied
prior art references, and the respective positions articulated
by appellant and the examiner. As a consequence of our
review, we will reverse the obviousness rejections of claims
81 through 85, 89, 97, and 101.
Independent claim 81 requires, in pertinent part, a time
measuring device which receives, at a first input, a test
signal and, at a second input, the same test signal after it
has been delayed by passing through the sensor being checked
for faults. In other words, the test signal must pass through
a sensor along one path to the time measuring device and must
go directly to the time measuring device along a second path.
Then, the time measuring device measures the time difference
between the test signal received at the two inputs.
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As pointed out by appellant (Brief, page 8), Leiber does
not detect faults in a sensor, but rather detects faults in
the control units of an antilocking brake system. Further,
the test signal of Leiber never passes through the sensor.
Although the examiner asserts that transducer 11 is a sensor
and that the test signal passes therethrough, as indicated by
appellant (Reply Brief, pages 2-3), transducer 11 is merely an
analog-to-digital converter, not a sensor. Even by the
examiner's own definition of the term "sensor" (Answer, page
5), transducer 11 cannot be a sensor, since it merely receives
a signal from a sensor element 10 but does not sense any
physical stimulus.
In addition, despite the examiner's assertions to the
contrary (Answer, page 4) appellant correctly indicates
(Brief, page 9) that Leiber does not measure the time
difference between when the first input receives the test
signal and when the second input receives the delayed test
signal. Leiber compares the sequences of pulses output by two
substantially identical control units and is not concerned at
all with the amount of delay through the sensor. In fact, as
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explained supra, the test signal never even passes through the
sensor and, therefore, cannot be delayed by it.
Thus, Leiber lacks significant limitations of claim 81.
The examiner, in the "Response to argument" section of the
answer, attempts to provide reasons for modifying Leiber to
meet the claims. For example, in response to Leiber's failure
to compare a test signal to a sensor-delayed test signal to
detect a fault in a sensor, the examiner explains (Answer,
page 7) that
although Leiber runs a test signal through a whole
control unit comprising transducer 11, processor 12,
logic 13 and logic 16 in order to detect a fault,
one of ordinary skill in the art would have found it
obvious to run a timing signal through whatever
portion of a system that was desired to be monitored
for faults. Thus, since Leiber teaches the basic
concept of measuring the time it takes a test signal
to be processed through a circuit and compare it to
a reference time, one of ordinary skill in the art
would have found this fault detection technique just
as applicable to wheel speed sensors ..., the
specific type of sensor not substantially affecting
how a fault is detected using test signal timing
comparison.
The examiner further states (Answer, page 8),
Although the generated test signal in Leiber
appears to be modified from an original state into a
signal sequence in order that testing of processor
and logic means can be realized, ... [o]ne of
ordinary skill in the art would have recognized that
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a less modified test signal could have been employed
in a circuit fault detection device, merely
depending on the type of sensor being tested, or the
number of potentially faulty elements in a tested
sensor circuit.
However, the examiner's conclusions are based on an
erroneous assumption that Leiber compares to a reference time
the time a test signal takes to pass through a circuit.
Leiber instead compares the test signal after it passes
through one circuit with the same test signal after it passes
through a second substantially identical circuit. Neither is
a reference time. Further, the examiner's proposed
modifications would involve a complete reconstruction of
Leiber's device with no indication from the art as to how one
would go about such a reconstruction. Lastly, that the prior
art can be modified in the manner suggested by the examiner
does not make the modification obvious unless the prior art
suggested the desirability of the modification. In re Fritch,
972 F.2d 1260, 1266, 23 USPQ2d 1780, 1783-4 (Fed. Cir. 1992).
Thus, the examiner has failed to establish a prima facie case
of obviousness. Consequently, we will not affirm the
rejection of claim 81 and its dependents, claims 82 through
85, and 89.
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Similar to claim 81, claim 97 recites transmitting to a
first input of a time measuring device a test signal and to a
second input the same test signal after it has been delayed by
passing through the sensor being checked for faults. As we
have already determined that Leiber fails to disclose checking
a sensor for faults, passing a test signal through the sensor,
and measuring the claimed time difference, we will reverse the
rejection of claim 97.
Claim 101, like claim 97, requires passing a test signal
through the sensor being tested for faults and measuring a
time difference (although for claim 101, the reference time is
the time the test signal is generated rather than the time it
is received at the first input). Leiber again falls short for
reasons substantially the same as those discussed supra.
Therefore, we cannot sustain the rejection of claim 101.
Regarding the rejections of claims 84, 85, and 89,
neither Buchschmid (for claims 84 and 89) nor Bleckmann (for
claim 85) cures the deficiencies of Leiber noted above.
Accordingly, we cannot sustain the rejection of claims 84, 85,
and 89.
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CONCLUSION
The decision of the examiner rejecting claims 81 through
85, 89, 97, and 101 under 35 U.S.C. § 103 is reversed.
REVERSED
JAMES D. THOMAS )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
ANITA PELLMAN GROSS ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
LANCE LEONARD BARRY )
Administrative Patent Judge )
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AG/RWK
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