Ex parte Baskett et al.

Board of Patent Appeals and Interferences

May 14, 2001

08722384 (B.P.A.I. May. 14, 2001)

Application for patent filed September 30, 1996,1
entitled "Circuit And Method Of Compensating For Membrane
Stress In A Sensor."
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The opinion in support of the decision being
entered today was not written for publication
and is not binding precedent of the Board.
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Paper No. 12
UNITED STATES PATENT AND TRADEMARK OFFICE

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES

Ex parte IRA E. BASKETT
and ANDREW C. McNEIL

Appeal No. 1998-1364
Application 08/722,3841

ON BRIEF

Before BARRETT, RUGGIERO, and LALL, Administrative Patent
Judges.
BARRETT, Administrative Patent Judge.
DECISION ON APPEAL
Appeal No. 1998-1364
Application 08/722,384
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This is a decision on appeal under 35 U.S.C. § 134 from
the final rejection of claims 1-22.
We affirm-in-part.
BACKGROUND
The invention relates to a sensor and method of sensing
membrane stress in a sensing structure such as a diaphragm.
The invention is clearly summarized in Appellants' brief in
the Summary of Invention at pages 2-3.
Claim 1 is reproduced below.
1. A sensor, comprising:
a sensing structure having a first location with
substantially zero bending in response to a physical
condition; and
a first transducer disposed at the first location
for converting a membrane stress in the sensing structure
to a first sense signal.
The Examiner relies on the following prior art:
Huck et al. (Huck) 5,107,710 April 28, 1992
Inoue et al. (Inoue) 5,166,892 November 24, 1992
Appeal No. 1998-1364
Application 08/722,384
Claim 10 has been inadvertently omitted from the2
Examiner's statements of the rejection. However, since it is
mentioned in the discussion of the anticipation rejection
(Final Rejection, p. 2), we include it in this claim grouping.
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Claims 1-4, 6, 7, 10, and 14-20 stand rejected under2
35 U.S.C. § 102(b) as being anticipated by Huck.
Claims 5, 11-13, and 21 stand rejected under 35 U.S.C.
§ 103(a) as being unpatentable over Huck.
Claims 8, 9, and 22 stand rejected under 35 U.S.C.
§ 103(a) as being unpatentable over Huck and Inoue.
We refer to the Final Rejection (Paper No. 5) (pages
referred to as "FR__") and the Examiner's Answer (Paper
No. 11) (pages referred to as "EA__") for a statement of the
Examiner's position, and to the Appeal Brief (Paper No. 10)
(pages referred to as "Br__") for Appellants' arguments
thereagainst.
OPINION
Claims 1 and 10-13
The Examiner finds that "Huck et al.[] disclose a
pressure sensor teaching the features of the claimed invention
including: a sensing structure having a first location with
zero bending (col. 3, lines 1-17), [and] a set of first
Appeal No. 1998-1364
Application 08/722,384
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transducer[s] disposed at this region[] (element[s] 26, 28, 30
and 36)" (FR2). The Examiner states for the first time in the
Examiner's Answer that "these claims do not support any
limitation to show that the membrane is stressed due to an
external physical force[;] it is clear that [the membrane] can
be stressed due to temperature variations which is indeed a
physical condition, as in the case of Huck et al." (EA5).
It is clear that the Examiner finds the claims
anticipated because they are so broad they read on Huck in an
unintended manner, rather than finding that Huck teaches the
disclosed pressure sensor structure. We agree with the
Examiner.
Claim 1 recites "a sensing structure having a first
location with substantially zero bending in response to a
physical condition." The "physical condition" is not defined
to be a force, such as a pressure. The term "sensing
structure" is defined (specification, p. 7, lines 27-30): "A
sensing structure is defined as the portion of a sensor which
produces a stress in response to a physical condition." The
term "sensor" is discussed as follows (specification, p. 1,
lines 9-16):
Appeal No. 1998-1364
Application 08/722,384
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Sensors are commonly used for converting physical
conditions such as temperature, pressure, and
acceleration to an electrical sensor signal for further
processing. A typical sensor, such as a pressure sensor,
includes a diaphragm for converting a pressure into a
stress. A transducer converts the stress into the sensor
signal which is typically amplified and filtered to
provide a sensor output signal. [Emphasis added.]
It is consistent with Appellants' specification to read
the "physical condition" in claim 1 on temperature and the
"sensing structure" on the surface of the diaphragm 16 in
Huck. The resistors 26-32 are deposited in the non-active (or
inactive) part 34 of the diaphragm 16 "to prevent their
resistance values from being changed by the mechanical
deformation of the diaphragm" (col. 3, lines 4-6). Since the
resistance values are not changed by mechanical deformation,
the inactive area 34 must be a "location of substantially zero
bending," as claimed. That is, claim 1 reads on a part of the
overall Huck sensor. Since Appellants themselves are claiming
only a part of an overall sensor, this interpretation is
reasonable.
Claim 1 further recites "a first transducer disposed at
the first location for converting a membrane stress in the
sensing structure to a first sense signal." The temperature
sensors R and R in Huck correspond to transducers in theT1 T2
Appeal No. 1998-1364
Application 08/722,384
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first location. The expansion and contraction of the surface
of diaphragm 16 in Huck due to temperature is considered to
produce a membrane stress, which is converted in the sensors
to a sense signal.
It appears that Huck establishes a prima facie case of
anticipation. We now consider Appellants' arguments.
Appellants arguments are based on the disclosed pressure
transducer rather than the broad language of claim 1. The
"physical condition" in claim 1 does not have to be a
condition that produces bending in the sensing structure, as
assumed in Appellants' arguments (Br5), but could be a
physical condition such as temperature. It is clear from
claim 14 that Appellants knew how to claim that the physical
condition produces bending, but elected not to include such
limitation in claim 1.
Appellants argue that "[m]embrane stress is a particular
type of stress that results from the sensing structure's
stretching in response to the applied physical condition"
(Br6) and that membrane stress is not present in the inactive
area 34 of Huck because the inactive area 34 is not deformed
by applied pressure (Br6). We find the expansion and
Appeal No. 1998-1364
Application 08/722,384
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contraction (stretching) of the surface of diaphragm 16 in
Huck due to temperature (the physical condition) results in a
membrane stress, which is sensed by the temperature sensors.
That is, it has not been shown that membrane stress, broadly,
is limited to stress produced by bending. Appellants'
arguments are based on membrane stress being caused by bending
due to physical conditions, which is not claimed.
Appellants argue that "the Huck pressure sensor does not
address the problem of sensor nonlinearity due to membrane
stress" (Br7) and operates in a fundamentally different way
(Br7). However, claim 1 does not recite a solution to this
problem; it merely recites a transducer at a particular
location. We are not persuaded that claim 1, as broadly
worded, distinguishes over Huck.
In summary, Appellants' arguments are not persuasive of
error in the finding of anticipation of claim 1. Claims 10-13
are said to be allowable for the reasons stated with respect
to claim 1 (Br9), which does not constitute an argument of
separate patentability. Thus, claims 10-13 fall with claim 1.
The rejections of claims 1 and 10-13 are sustained.
Claims 2-9
Appeal No. 1998-1364
Application 08/722,384
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Claim 2 recites that "the substantially zero bending
occurs at a transition between tensile stress and compressive
stress at a surface of the sensing structure in response to
the physical condition." This implicitly requires bending in
a constrained structure so as to produce an inflection point
between tensile stress and compressive stress, as shown in
Appellants' figure 2. Since no bending occurs in the inactive
area 34 of Huck, there is no transition between tensile stress
and compressive stress in Huck. Thus, we find that claim 2 is
not anticipated. Claims 3-7, which depend on claim 2 and are
rejected as being anticipated by, or unpatentable over, Huck
incorporate the limitation of claim 2 and are patentable
thereover. Inoue, which is applied to the rejection of
claims 8 and 9 to show an error compensation circuit, does not
cure the deficiency of Huck with respect to claim 2. For
these reasons, the rejections of claims 2-9 are reversed.
Claims 14-17
Independent claim 14 recites a first step of "providing a
sensing structure that bends in response to a physical
condition and develops a membrane stress at a first location
that has substantially zero bending." Thus, claim 14 is not
Appeal No. 1998-1364
Application 08/722,384
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just a method counterpart to claim 1, but is narrower than
claim 1 in that it specifically recites that the sensing
structure bends in response to a physical condition.
Accordingly, the broad interpretation taken with respect to
claim 1 does not apply here. The corresponding sensing
structure in Huck is the active area 17 of the diaphragm 16,
not the inactive area 34 (which does not bend). There is no
disclosure in Huck of any of the sensors R -R in the active1 4
area 17 being at a location of substantially zero bending.
Therefore, we find that Huck does not anticipate claim 17 or
claims 15-17. The rejection of claims 15-17 is reversed.
Claims 18-22
Claim 18 recites, in part, "a sensing structure having a
first location with substantially zero bending and a second
location that bends in response to a physical condition." The
"physical condition" has to be the kind of condition that
produces bending in part of the sensing structure, e.g., a
force or pressure. However, so far, claim 18 is broad enough
to read the "first location" on the inactive area 34 of the
sensor in Huck and the "second location" on the active area 17
of Huck.
Appeal No. 1998-1364
Application 08/722,384
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Claim 18 further recites "a first transducer disposed at
the first location of the sensing structure for providing a
first sense signal representative of an error component
introduced by a membrane stress in the sensing structure in
response to the physical condition." At this point, we see a
contradiction that prevents claim 18 from reading on Huck.
The temperature sensors in Huck, which correspond to the first
transducer in the Examiner's interpretation, do not produce
"an error component introduced by a membrane stress in the
sensing structure in response to the physical condition"
because the "physical condition" has to be the kind of
condition that produces bending, e.g., a pressure, not just
any physical condition, e.g., temperature. We find that
claim 18 is not anticipated by Huck. Claims 19-21, which
depend on claim 18 and are rejected as being anticipated by,
or unpatentable over, Huck incorporate the limitations of
claim 18 and are patentable thereover. Inoue, which is
applied to the rejection of claim 22 to show an error
compensation circuit, does not cure the deficiency of Huck
with respect to claim 18. For these reasons, the rejections
of claims 18-22 are reversed.
Appeal No. 1998-1364
Application 08/722,384
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CONCLUSION
The rejections of claims 1 and 10-13 are sustained.
The rejections of claims 2-9 and 14-22 are reversed.
No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
§ 1.136(a).
AFFIRMED-IN-PART
LEE E. BARRETT )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
JOSEPH F. RUGGIERO ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
PARSHOTAM S. LALL )
Administrative Patent Judge )
Appeal No. 1998-1364
Application 08/722,384
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Vincent B. Ingrassia
MOTOROLA, INC.
Intellectual Property Department
Suite R3108
P.O. Box 10219
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