Ex parte Postma

Board of Patent Appeals and Interferences

Jan 27, 1999

08101324 (B.P.A.I. Jan. 27, 1999)

Application for patent filed August 2, 1993, entitled1
"Magnetic Head Having A Multilayer Structure And Method Of
Manufacturing The Magnetic Head," which claims the foreign
filing priority benefit under 35 U.S.C. § 119 of European
Patent Office Application 92202435.1, filed August 6, 1992.
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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journal and (2) is not binding precedent of the Board.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. 21
UNITED STATES PATENT AND TRADEMARK OFFICE

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES

Ex parte LAMBERTUS POSTMA

Appeal No. 96-1841
Application 08/101,3241

ON BRIEF

Before JERRY SMITH, BARRETT, and TORCZON, Administrative
Patent Judges.
BARRETT, Administrative Patent Judge.
DECISION ON APPEAL
Appeal No. 96-1841
Application 08/101,324
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This is a decision on appeal under 35 U.S.C. § 134 from
the final rejection of claims 1-6 and 8-16. Claim 7 has
been canceled.
We affirm.
BACKGROUND
The disclosed invention is directed to the structure of
a magnetic head for detecting a magnetic field.
Claim 1, the sole independent claim, is reproduced
below.
1. A magnetic head for detecting a magnetic field
representing information recorded on a magnetic
recording medium, said magnetic head having a head face
and comprising a multilayer structure with at least one
magnetoresistive layer of magnetic anisotropic
material, said magnetoresistive layer having a central
portion forming a magnetoresistive element located
between two end portions, said magnetoresistive layer
having a longitudinal axis directed from one end
portion to the other end portion, said magnetoresistive
element having an easy axis of magnetization extending
at least substantially parallel to the longitudinal
axis, an electrically conducting layer provided on one
side of said magnetoresistive layer, said conducting
layer comprising at least one equipotential strip which
extends at an angle to the longitudinal axis,
characterized in that located opposite each end
portion, on a side of the magnetoresistive element
remote from the conducting layer is a facing layer of
hard-magnetic material having an axis of magnetization
extending parallel to the longitudinal axis of the
magnetoresistive layer, and in that a non-magnetic
spacer layer of electrically insulating material is
Appeal No. 96-1841
Application 08/101,324
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present between each end portion and the facing layer
of hard-magnetic material.
The examiner relies on the following prior art
references:
Kuijk (Kuijk '748) 4,052,748 October 4,
1977
Smith 4,903,158 February 20,
1990
We note that the examiner cites Kuijk, U.S. Patent 4,122,505
(Kuijk '505), issued October 24, 1978, in the listing of
prior art relied upon in the rejection (Examiner's Answer,
page 2), while the statement of the rejection in the Final
Rejection and the Examiner's Answer relies on Kuijk '748.
In the Examiner's Answer, the examiner appears to confuse
Kuijk '505 with Kuijk '748 since the examiner's references
to line numbers (e.g., col. 1, lines 38-59 and lines 38-37
cited in the Examiner's Answer, page 5) correspond exactly
to paragraphs in Kuijk '505 and references to element
numbers (i.e., electrical layer 4/5/9 mentioned in the
Examiner's Answer, page 5) correspond to element numbers in
Kuijk '505. We treat the rejection as being over Kuijk '748
to be consistent with the statement of the rejection.
Claims 1-6 and 8-16 stand rejected under 35 U.S.C.
§ 103 as being unpatentable over Smith and Kuijk '748.
Appeal No. 96-1841
Application 08/101,324
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We refer to Final Rejection (Paper No. 9) (pages
referred to as "FR__") and the Examiner's Answer (Paper
No. 16) (pages referred to as "EA__") for a statement of the
examiner's position and to the Substitute Appeal Brief
received August 30, 1995, (Paper No. 15) (pages referred to
as "Br__") for a statement of appellant's position.
OPINION
Claims 1-6 and 8-16 are argued to stand or fall
together. Accordingly, the claims stand or fall together
with claim 1. In the examiner's statement that "Appellant's
brief includes a statement that claims 1-6 and 8-16 stand or
fall together and provides reasons as set forth in 37 C.F.R.
§ 1.192(c)(5) and (c)(6)," (emphasis added) (EA2), the
underlined portion should have been omitted since it applies
only when appellant desires to argue the claims separately.
We note, however, that there appears to be no form paragraph
in the Manual of Patent Examining Procedure § 1208 which
covers the situation where the claims are argued to stand or
fall together.
The level of ordinary skill is not argued, so we find
the patents to Smith and Kuijk '748, applied in the
Appeal No. 96-1841
Application 08/101,324
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rejection and the patent to Krounbi et al., U.S. Patent
5,005,096, incorporated by reference into appellant's
specification, to be representative of the level of ordinary
skill in the art. See In re Oelrich, 579 F.2d 86, 91,
198 USPQ 210, 214 (CCPA 1978) ("the PTO usually must
evaluate both the scope and content of the prior art and the
level of ordinary skill solely on the cold words of the
literature"); In re GPAC Inc., 57 F.3d 1573, 1579,
35 USPQ2d 1116, 1121 (Fed. Cir. 1995) (the Board did not err
in adopting the approach that the level of skill in the art
was best determined by the references of record). In
addition, those of ordinary skill in the art must be
presumed to know something about the art apart from what the
references expressly disclose. In re Jacoby, 309 F.2d 513,
516, 135 USPQ 317, 319 (CCPA 1962).
We agree with the examiner's conclusion that "[i]t
would have been obvious to a person of ordinary skill in the
art at the time the invention was made to bias the MR head
of Smith with slanted equipotential strips as suggested by
Kuijk ['748]" (EA4). It is considered well known to those
of ordinary skill in the MR sensor art that it is necessary
Appeal No. 96-1841
Application 08/101,324
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to provide two bias fields for an MR head to operate
optimally: one bias field to bias the MR material so that
its response to a flux field is linear and one bias field in
the longitudinal direction to suppress Barkhausen noise
which originates from multi-domain activities in MR
elements. The clearest statement of this is found in the
admitted prior art to Krounbi (col. 1), incorporated by
reference in the specification at page 3, which is
considered knowledge of those of ordinary skill in the art.
However, Smith also describes these two bias fields (col. 1,
line 28 to col. 2, line 32). As to the linearizing bias
field, Smith states (col. 1, lines 35-38): "As is fairly
conventional, source of hard (vertical) axis bias field,
provided for through a variety of means, biases the
ordinarily longitudinal moment to an orientation, as
depicted." Smith discloses using a permalloy layer 32,
which is magnetized by current through the sense film 33 "so
as to set up a hard axis bias field which biases the moment
of the film 33 at about 45E relative to the direction of
current flow . . ." (col. 2, lines 64-66). Kuijk '748,
which is incorporated by reference into the specification at
Appeal No. 96-1841
Application 08/101,324
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page 1, describes a structure having equipotential strips
for biasing the MR material so as to linearize the
reproduction. In our opinion, one of ordinary skill in the
MR sensor art would have recognized that the structure in
Kuijk '748 could be substituted as one of the "variety of
means" to bias the MR element in Smith. Appellant does not
argue why such a substitution of one well-known biasing
structure for another would have been nonobvious to one
having ordinary skill in the MR sensor art. In addition, we
refer to the discussion of Krounbi, infra, for its teaching
of using alternate biasing techniques.
We also agree with the examiner's statement that
"[a]lternatively, it would have been obvious to a person
having ordinary skill in the art at the time the invention
was made to provide the MR head of Kuijk ['748] with a
hard-magnetic layer and spacer as taught by Smith" (EA5).
The two bias fields provide separate functions. One skilled
in the MR art would have sought to use the hard-magnetic
material 42 and insulating layer 40 as taught in Smith with
a MR head for the described purpose of suppressing
Barkhausen noise.
Appeal No. 96-1841
Application 08/101,324
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Appellant argues that "[s]ince the Koijak [sic] patent
and the Smith patent are directed to completely unrelated
problems a person of ordinary skill in the art would find
nothing in these patents to combine their teachings" (Br7).
The examiner states that both Smith and Kuijk '748 are "both
concerned with linearizing the output signal of a head"
(EA7-8) and "[b]oth Smith and Kuijk bias the MR head about
45 degrees relative to the current flow" (EA8). Since both
Kuijk '748 and Smith are in the same field endeavor of MR
sensors, one of ordinary skill in the art would have
recognized that the teachings of one could be applied to the
other. The suggestion to modify the references has been
discussed, supra.
Appellant further argues that the combination of
teachings of Kuijk and Smith would not produce the claimed
invention because a person of ordinary skill would follow
the teachings of Smith in which the electrically conducting
layer (the bonding pads 34 and 36) is between the
magnetoresistive element and the spacer layer of
electrically insulating material, whereas claim 1 calls for
the spacer layer to be on a side of the magnetoresistive
Appeal No. 96-1841
Application 08/101,324
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layer remote from the electrically conducting layer. In the
Final Rejection, the examiner concluded that, with respect
to the order of layers, it would have been obvious to
rearrange the layers of Smith in a particular sequence
"since it is [sic, was] well within the purview of a skilled
artisan and absent an unobvious result" (FR4). Appellant
does not provide any argument why this statement is
erroneous. In the Examiner's Answer, the examiner states
that one of ordinary skill in the art "would have realized
that as long as the hard layer is enclosed by non-magnetic
layers and as long as the MR layer is contacting the
electrical layer the arrangement with respect to the
substrate need not be in a specific order" (EA6 and EA9).
We agree with the examiner that one of ordinary skill
in the art had sufficient skill to reorder the sequence of
layers, e.g., for manufacturing reasons. It would have been
more persuasive to us if the examiner had cited a reference.
However, appellant does not contest the examiner's statement
that rearrangement is within the knowledge and skill of one
in the art of MR sensors. It may be that the examiner's
statement is not contested because of the teachings of
Appeal No. 96-1841
Application 08/101,324
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Krounbi, incorporated by reference in the specification at
page 3. Figure 3 of Krounbi discloses an electrical
conductor layer 26, hard magnetic layer 16, nonmagnetic
spacer layer 18, MR layer 11, nonmagnetic spacer layer 22,
and soft magnetic film layer 20, in that order. The soft
magnetic layer 20 in Krounbi evidently serves the same
function of biasing the MR element as the magnetically soft
material layer 32 in Smith. Krounbi states (col. 4, lines
53-62):
[I]t will be understood by those skilled in the art
that various other changes in the form and details may
be made therein without departing from the spirit and
scope of the invention. For example, the conductor
leads may be placed on the opposite side of the MR
layer, if desired, and the MR sensor may also include
other layers as is known in the art such as biasing
layers, for example. Alternate transverse biasing
techniques such as electrical shunt bias, and
barberpole can also be used in the active region 12 of
the MR sensor 10. [Emphasis added.]
Therefore, the admitted prior art incorporated by reference
into appellant's specification discloses that one of
ordinary skill in the art would have understood that the
layers could be reordered, including, expressly, locating
the conductive leads on the opposite side of the MR layer
from the hard magnetic layer and nonmagnetic spacer layer.
Appeal No. 96-1841
Application 08/101,324
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This supports our conclusion that it would have been obvious
to locate the electrically conducting layer in Smith
(bonding pads 34 and 36) on the opposite side of the MR film
33, between the magnetic insulating coating 31 and the
MR film 33. In addition, the last sentence quoted above
indicates that a "barberpole" bias technique could be used
in place of the layer of soft magnetic material, which
apparently refers to the use of equipotential strips (see
Kuijk '505). This supports our conclusion that it would
have been obvious to substitute equipotential strips for a
layer of soft magnetic material. Because Krounbi discloses
a barberpole as an alternative bias technique, we disagree
with appellant's description of the teachings of Krounbi in
the specification at page 3.
For the reasons stated above, the rejection of claims
1-6 and 8-16 is sustained.
Appeal No. 96-1841
Application 08/101,324
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No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
§ 1.136(a).
AFFIRMED
JERRY SMITH )
Administrative Patent Judge )
)
)
)
) BOARD OF
PATENT
LEE E. BARRETT ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
RICHARD TORCZON )
Administrative Patent Judge )
Appeal No. 96-1841
Application 08/101,324
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