Ex parte Yamakoshi et al.

Board of Patent Appeals and Interferences

Aug 12, 1999

08475062 (B.P.A.I. Aug. 12, 1999)

The application, entitled “Digital Magnetic Reproduction1
Apparatus and Digital Magnetic Recording/Reproducing
Apparatus” was filed June 7, 1995. The application is a
divisional of Application Serial No. 08/284,238, which was
filed August 2, 1994, and is now abandoned.
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today (1) was not written
for publication in a law journal and (2) is not binding precedent of the Board.
Paper No. 16
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte TAKAMICHI YAMAKOSHI, YOSHIHARU SHIMANO, and HIROAKI
YADA
____________
Appeal No. 97-1167
Application No. 08/475,0621
____________
HEARD: August 5, 1999
____________
Before URYNOWICZ, HAIRSTON and BARRY, Administrative Patent
Judges.
BARRY, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on the appeal under 35 U.S.C. § 134
from the final rejection of claims 3, 6, and 11-15. The
Appeal No. 97-1167
Application No. 08/475,062
appellants filed an amendment after final rejection on
September 6, 1996, which was entered. We reverse.
Appeal No. 97-1167 Page 3
Application No. 08/475,062
BACKGROUND
The invention at issue in this appeal relates to digital
magnetic recording. It is an apparatus for recording (i.e.,
writing) data on and reproducing (i.e., reading) data from a
magnetic disk. More specifically, the apparatus includes a
distortion detector, a measuring circuit, and a bias control
circuit. The distortion detector measures a second harmonic
distortion (SHD) of a reproduced signal; the measuring circuit
measures the signal-to-noise (S/N) ratio of the reproduced
signal. The bias control circuit controls the bias current in
the reproducing head to maintain the SHD at or below -25 dB
while maximizing the S/N ratio. By maximizing the S/N ratio
while maintaining the SHD at or below this level, the
apparatus minimizes the bit error rate of the data it
reproduces.
Claim 3, which is representative for our purposes,
follows:
3. A digital magnetic reproducing apparatus
comprising a reproducing head to reproduce data from
a magnetic recording medium; an equalizer for
shaping, by a partial response method, a waveform of
the reproduced signal output from said reproducing
Appeal No. 97-1167 Page 4
Application No. 08/475,062
head, and a decoder for decoding, by a maximum
likelihood decoding method, an equalized reproduced
signal obtained from said equalizer;
said apparatus further comprising:
a distortion detector for measuring a second
harmonic distortion of the reproduced signal;
a decision circuit for making a decision as to
whether or not the second harmonic distortion is -25
dB or lower;
a measuring circuit for measuring a signal-to-
noise ratio of the reproduced signal, and
a bias current control circuit supplied with the
results of both said decision circuit and said
measuring circuit, and controlling the bias current
in said reproducing head in such a manner that the
signal-to-noise ratio becomes highest in a range
where the second harmonic distortion of the
reproduced signal is -25 dB or lower.
The references relied on by the patent examiner in
rejecting the claims follow:
Tin 4,280,153 Jul. 21,
1981
Shimotashiro et al. (Shimotashiro) 5,124,861 Jun.
23, 1992
Ottesen et al. (Ottesen) 5,301,080 Apr.
5, 1994
(filed Dec. 31,
1992).
Claims 3, 11, 13, and 15 stand rejected under 35 U.S.C.
§ 103 as obvious over admitted prior art (Admission) in view
of Ottesen and Shimotashiro. (Final Rejection at 5.) Claims
6, 12, and 14 stand rejected under § 103 as obvious over
Appeal No. 97-1167 Page 5
Application No. 08/475,062
Admission in view of Ottesen and Shimotashiro further in view
of Tin. (Id. at 7.) Rather than repeat the arguments of the
appellants or examiner in toto, we refer the reader to the
appeal and reply briefs and the examiner’s answer for the
respective details thereof.
Appeal No. 97-1167 Page 6
Application No. 08/475,062
OPINION
In reaching our decision in this appeal, we considered
the subject matter on appeal and the rejections and evidence
advanced by the examiner. We also considered the appellants’
and examiner’s arguments. After considering the record before
us, it is our view that the evidence and level of skill in the
art would not have suggested to one of ordinary skill in the
art the invention of claims 3, 6, and 11-15. Accordingly, we
reverse.
We begin our consideration of the patentability of the
claims by recalling that in rejecting claims under 35 U.S.C.
§ 103, the patent examiner bears the initial burden of
establishing a prima facie case of obviousness. A prima facie
case is established when the teachings from the prior art
itself would appear to have suggested the claimed subject
matter to a person of ordinary skill in the art. If the
examiner fails to establish a prima facie case, an obviousness
rejection is improper and will be overturned. In re
Rijckaert, 9 F.3d 1531, 1532, 28 USPQ2d 1955, 1956 (Fed. Cir.
Appeal No. 97-1167 Page 7
Application No. 08/475,062
1993). With this in mind, we analyze the examiner’s
rejections.
The examiner rejects claims 3, 11, 13, and 15 as obvious
over Admission in view of Ottesen and Shimotashiro. At the
outset, we observe that the examiner fails to map the language
of the claims to the disclosures of the Admission or
references. Instead, he begins the rejection by
characterizing Admission as follows.
On lines 7-16 of page 1, applicant admits that
“there is currently in progress the introduction of
a signal processing method ... which is a
combination of partial response equalization and
maximum likelihood decoding". For dependent claims
11 and 13, [Admission] employs a magnetoresistance
effect head as a reproducing transducer and uses a
magnetic disk as a recording medium. (Final
Rejection at 5.)
He admits that Admission “neither measures second harmonic
distortion nor signal to noise ratio.” (Id.)
The examiner makes the following observation about
Ottesen.
Ottesen ... provides a bias servo loop for a
magneto- resistive head. FIR bandpass filter 20 and
RMS amplitude estimator 24 measure the second
Appeal No. 97-1167 Page 8
Application No. 08/475,062
harmonic distortion of the reproduced signal.
Decision circuit 26 compares the second harmonic
distortion with a reference 28. Current driver 12
adjusts the bias current based on the output of
decision circuit 26. (Id.)
He concludes that it would have been obvious to combine
Ottesen with Admission “to provide dynamic control of a
reproducing head, to maintain it at an optimum operating point
....” (Id. at 5-6.)
The examiner admits that the combination of Admission in view
of Ottesen “lacks a circuit for measuring the signal to noise
ratio of the reproduced signal.” (Id. at 6.)
He notes that Shimotashiro “selects the bias current
value as an optimum value for maximizing an overall S/N ratio.
Adder 12 combines the S/N ratio resulting from noise with a
S/N ratio resulting from distortion. In this way,
Shimotashiro ... teach[es] combining noise and distortion
measurement to optimize bias current.” (Id.) The examiner
concludes that it would have been obvious to combine
Shimotashiro with Ottesen in view of Admission “to enable a
higher recording rate and increase efficiency ....” (Id.)
Appeal No. 97-1167 Page 9
Application No. 08/475,062
The examiner rejects claims 6, 12, and 14 as obvious over
the combination of Admission in view of Ottesen and
Shimotashiro “as applied to claim[s] 3, 11, 13, and 15 above,”
(id. at 7), further in view of Tin. He begins the rejection
by admitting that the combination “does not disclose delaying
data with respect to a reference clock signal.” (Id.) The
examiner observes that Tin “provides a reference clock
generator 12 and a delay circuit 20. As depicted in Figure 4,
the time interval T corresponds to a delay between recording
an elementary information on tape by head 41 and reproducing
the same information by head 42.” (Id.) The examiner
concludes that it would have been obvious to combine Tin with
Admission in view of Ottesen and Shimotashiro “to compensate
for the distance between the recording and reproducing heads,
as suggested by Tin on lines 16-17 of column 2.” (Id.)
Although the references omit “the -25 dB limitation,”
(id. at 6), which is recited in each of the claims, the
examiner notes that Ottesen teaches “that reference 28 may
vary depending on the changing environment.” (Id.) “Since
applicant has not disclosed that -25 dB is a critical range,”
Appeal No. 97-1167 Page 10
Application No. 08/475,062
opines the examiner, “selection of such a range in [sic, is]
considered merely optimization of a range and does not
patentably define over Ottesen ..., especially since no new
and unexpected results are submitted by applicant. See In re
Aller, 105 USPQ 233 (CCPA 1955).” (Id.)
The U.S. Court of Customs and Patent Appeals (CCPA)
established the rule that the discovery of an optimum value of
a variable in a known process is normally obvious. In re
Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). As
with many rules, there are exceptions to the CCPA’s rule. One
exception is the case where a parameter being optimized was
not recognized to
be a “result-effective variable.” In re Yates, 663 F.2d 1054,
1057, 211 USPQ 1149, 1151 (CCPA 1981); In re Antonie, 559 F.2d
618, 621, 195 USPQ 6, 9 (CCPA 1977). We find this exception
applies here.
In determining whether the invention as a whole would
have been obvious under § 103, we must first delineate the
invention as a whole. In delineating the invention as a
Appeal No. 97-1167 Page 11
Application No. 08/475,062
whole, we look to the subject matter recited in the claim and
to those properties of the subject matter disclosed in the
specification. Antonie, 559 F.2d at 619, 195 USPQ at 8.
Here, the invention as a whole is maintaining the SHD of a
reproduced signal at or below -25 dB,
(Spec. at 9), and its disclosed property. The property is
that by maintaining the SHD at or below such a level, the
invention minimizes the bit error rate of data it reproduces.
(Id.)
The controlling question is simply whether the
differences, viz., namely the value of -25 dB and its
property, between the prior art and the appellants’ invention
as a whole are such that the invention would have been
obvious. The answer is no. The examiner has not shown that
the prior art as a whole recognized that the bit-error-rate
depends on the SHD. Recognition of this dependence is
essential to the obviousness of conducting experiments to
decide the value of the SHD that will offer an acceptable bit-
error-rate. Such dependence can be determined from data
representing bit-error-rate versus SHD as revealed by the
Appeal No. 97-1167 Page 12
Application No. 08/475,062
appellants. (Id., Fig. 3) The examiner has given us no basis
for the obviousness of the necessary experiments apart from
the appellants’ disclosure thereof.
For these reasons, the examiner failed to show that SHD
was recognized to be a result-effective variable. Therefore,
we find the examiner’s rejection does not amount to a prima
facie case of obviousness. Because the examiner has not
established a prima facie case, the rejection of claims 3, 11,
13, and 15 as obvious over Admission in view of Ottesen and
Shimotashiro and of claims 6, 12, and 14 as obvious over
Admission in view of Ottesen and Shimotashiro further in view
of Tin are improper and are reversed.
CONCLUSION
To summarize, the decision of the examiner to reject
claims 3, 6, and 11-15 under 35 U.S.C. § 103 is reversed.
Appeal No. 97-1167 Page 13
Application No. 08/475,062

REVERSED
STANLEY M. URYNOWICZ, JR. )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
KENNETH W. HAIRSTON ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
LANCE LEONARD BARRY )
Administrative Patent Judge )
Appeal No. 97-1167 Page 14
Application No. 08/475,062
HILL STEADMAN & SIMPSON,
A PROFESSIONAL CORPORATION
85TH FLOOR, SEARS TOWER
CHICAGO, IL 60606
APPEAL NO. 97-1167 - JUDGE BARRY
APPLICATION NO. 08/475,062
APJ BARRY
APJ HAIRSTON
APJ URYNOWICZ
DECISION: REVERSED
Prepared by: Gloria Henderson
DRAFT TYPED: 01 Aug 00
FINAL TYPED:
Gloria, note the following instructions:
Do NOT change style of citations.
Do insert claim and reference(s).
Do check quotations.
Do proofread.