       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                ______________________

          IN RE HITACHI METALS, LTD.,
                      Appellant
               ______________________

                      2014-1689
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in Serial No.
90/010,759.
                 ______________________

               Decided: March 17, 2015
               ______________________

    JOHN FRANK MURPHY, Baker & Hostetler LLP, Phila-
delphia, PA, argued for appellant. Also represented by
BARRY EASTBURN BRETSCHNEIDER, WILLIAM THOMAS DE
VINNEY, Washington, DC.

   JEREMIAH HELM, Office of the Solicitor, United States
Patent and Trademark Office, Alexandria, VA, argued for
appellee Michelle K. Lee. Also represented by NATHAN K.
KELLEY, LORE A. UNT.
                 ______________________

Before PROST, Chief Judge, PLAGER and WALLACH, Circuit
                        Judges.
2                                IN RE: HITACHI METALS, LTD.




PROST, Chief Judge.
    This appeal arises from an ex parte reexamination of
U.S. Patent No. 5,645,651 (“’651 patent”) where the
Patent and Trademark Appeals Board (“Board”) found
that claims 1, 2, 6, 7, and 15-24 of the ’651 patent were
invalid for obviousness-type double patenting over claims
1, 3, 13, 16, 29, and 34 of U.S. Patent No. 4,792,368 (“’368
patent”). Hitachi now appeals the Board’s decision.
Because the Board correctly determined that the claims
are unpatentable for obviousness-type double patenting,
this court affirms.
                       BACKGROUND
    The invention at issue relates to temperature depend-
ency improvements in magnetic materials, including
permanent magnets, that are based on a Fe-B-R com-
pound, where Fe represents iron, B represents boron, and
R represents a rare earth metal. These compounds are
crystalline structures that are substantially a tetragonal
system. According to the patent, these crystalline com-
pounds “are advantageous in that they can be obtained in
the form of at least as-cast alloys, or powdery or granular
alloys or sintered bodies in any desired shapes, and
applied to magnetic recording media (such as magnetic
recording tapes) as well as magnetic paints, magneto-
stractive materials, thermosensitive materials and the
like.” ’651 patent col. 4 ll. 7-13. Additionally the inven-
tion can be used as an intermediary step to creating a
permanent magnet. Id. at ll. 13, 14.
    The present case focuses on two Hitachi patents,
the ’368 patent, issued on December 20, 1988 from an
application filed on July 25, 1983, and the ’651 patent,
issued on July 8, 1997 from an application filed on June 7,
1995. Hitachi was granted a seventeen-year patent term
for the ’368 patent on December 20, 1988 and a seven-
teen-year patent term for the ’651 patent on June 7, 1995.
IN RE: HITACHI METALS, LTD.                               3



Thus, the ’651 patent’s term extends almost nine years
beyond the ’368 patent.
    The ’368 patent is directed to crystalline compounds
based on an alloy system of R(Fe,Co)B. The claimed
crystalline compounds also contain additional elements
from the defined class termed M. Claim 13 of the ’368
patent is representative and reads:
        An anisotropic magnetic material having a
    mean crystal grain size of at least about 1 micron
    and an intrinsic coercivity of at least 1 kOe, and
    having a maximum energy product of at least 10
    MGOe upon sintering, said material consisting es-
    sentially of, by atomic percent, 12-20 percent R
    wherein R is at least one element selected from
    the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho,
    Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and where-
    in at least 50% of R consists of Nd and/or Pr, 5-18
    percent B, at least one additional element M se-
    lected from the group given below in the amounts
    of no more than the atomic percentages specified
    below wherein when more than one element com-
    prises M, the sum of M is no more than the maxi-
    mum value of any one of the values specified
    below for M actually added and the balance being
    at least 62 percent Fe, in which Co is substituted
    for Fe in an amount greater than zero and up to
    25 percent of the material and a crystal phase of a
    ferromagnetic compound having an (Fe,Co)-B-R
    type tetragonal crystal structure occupies at least
    50 vol% of the entire material: 3.4% Ti, 6.5% Ni,
    5.0% Bi, 6.8% V, 9.6% Nb, 8.3% Ta, 5.4% Cr, 6.1%
    Mo, 6.0% W, 6.0% Mn, 6.3% Al, 1.3% Sb, 4.2% Ge,
    2.0% Sn, 4.2% Zr, and 4.2% Hf; and which has a
    higher Curie Temperature than a corresponding
    ferromagnetic Fe-B-R-M base composition con-
    taining no Co and having said crystal structure.
4                                 IN RE: HITACHI METALS, LTD.




    The ’651 patent also claims a crystalline compound
based on an alloy system of R(Fe,CO)B. The claimed
crystalline compound contains additional elements from
defined classes termed: X, A, and M. Claim 1 of the ’651
patent is representative and reads:
         A crystalline R(Fe,Co)BXAM compound hav-
    ing a stable tetragonal crystal structure having
    lattice constants of ao about 8.8 angstroms and co
    about 12 angstroms, in which R is at least one el-
    ement selected from the group consisting of Nd,
    Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm,
    Yb, Lu and Y, X is at least one element selected
    from the group consisting of S, C, P and Cu, A is
    at least one element selected from the group con-
    sisting of H, Li, Na, K, Be, Sr, Ba, Ag, Zn, N, F,
    Se, Te and Pb, and M is at least one element se-
    lected from the group consisting of Ti, Ni, Bi, V,
    Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf and
    Si.
    An ex parte reexamination of the ’651 patent was re-
quested on December 7, 2009. The examiner issued seven
rejections, one of which was a rejection of claims 1, 2, 6, 7,
and 15-24 for obviousness-type double patenting over
the ’368 patent. Hitachi subsequently appealed to the
Board. The Board reversed all of the examiner’s rejec-
tions, and while agreeing that the claims of the ’651
patent represent obvious variants of the claims of the ’368
patent, the Board designated its analysis as a new ground
of rejection pursuant to 37 C.F.R. § 41.50(b) as the
Board’s analysis differed from that of the examiner’s.
Hitachi then requested a rehearing, which was denied.
                        DISCUSSION
    The court has jurisdiction over this appeal pursuant
to 35 U.S.C. § 134(b), 35 U.S.C. § 141(b), and 28 U.S.C.
§ 1295(a)(4)(A).
IN RE: HITACHI METALS, LTD.                                 5



                  A. Standard of Review
    Whether a claimed invention is unpatentable as obvi-
ous under 35 U.S.C. § 103 is a question of law based on
underlying findings of fact. In re Gartside, 203 F.3d 1305,
1316 (Fed. Cir. 2000). Therefore, when the board deter-
mines that a patent’s claims are unpatentable under
§ 103, this court reviews the board’s legal conclusions de
novo and the board’s factual findings for substantial
evidence. Id.
            B. Obvious-Type Double Patenting
    Obviousness-type double patenting is a judicially cre-
ated doctrine that “prevents the extension of the term of
the original patent via the patenting of an obvious varia-
tion.” Georgia-Pac. Corp. v. U.S. Gypsum Co., 195 F.3d
1322, 1326 (Fed. Cir. 1999) opinion amended on reh’g, 204
F.3d 1359 (Fed. Cir. 2000). “Under obviousness-type
double patenting, a patent is invalid when it is merely an
obvious variation of an invention disclosed and claimed in
an earlier patent by the same inventor.” Id. The deter-
mination of whether there is obviousness-type double
patenting is a two-step process:
         [1.] [The] court construes the claim in the ear-
    lier patent and the claim in the later patent and
    determines the differences.
        [2.] [T]he court determines whether the differ-
    ences in subject matter between the two claims
    render the claims patentably distinct. A later pa-
    tent claim is not patentably distinct from an earli-
    er patent claim if the later claim is obvious over,
    or anticipated by, the earlier claim.
Eli Lilly & Co. v. Barr Labs. Inc., 251 F.3d 955, 968 (Fed.
Cir. 2001) (citations omitted).
    A determination that there is obviousness-type double
patenting must be based on the matter actually claimed;
6                                 IN RE: HITACHI METALS, LTD.




reliance on the specification and not the claims is legal
error. In re Longi, 759 F.2d 887, 893 (Fed. Cir. 1985); see
also Application of Vogel, 422 F.2d 438, 441 (CCPA 1970)
(“[T]he patent disclosure may not be used as prior art.”).
However, this does not mean that the court must close its
eyes to the specification entirely. For example, the court
may look to the specification to define terms found in the
claims. Application of Vogel, 422 F.2d at 441. Additional-
ly, in answering the question, “Does any claim in the
application define merely an obvious variation of an
invention disclosed and claimed in the [prior] patent?”
the court may look to the various embodiments described
in the specification as they provide a tangible and more
meaningful method to discern whether what is claimed
was merely modified in an obvious manner. Id. As this
court’s predecessor has held, the use of the specification in
this manner “is not in contravention of the cases forbid-
ding its use as prior art, nor is it applying the patent as a
reference under 35 U.S.C. § 103 . . . .” Id. at 442. Thus in
limited circumstances, we may turn to the specification in
the analysis of whether there is obviousness-type double
patenting.
    In accordance with the two-prong obviousness-type
double patenting test, we first construe the claims at
issue and determine the differences in subject matter
between the claims.
    The relevant claims of the ’368 patent claim a crystal-
line compound with a tetragonal structure with the gen-
eral formula R(Fe,Co)B. Additionally, the claims require
at least one element from each of its claimed R and M
groups. Groups R and M are composed of the following
elements: Group R is composed of elements Nd, Pr, La,
Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu, and Y;
and Group M is composed of elements Ti, Ni, Bi, V, Nb,
Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, and Hf. Therefore,
to satisfy the relevant claims of the ’368 patent, the
IN RE: HITACHI METALS, LTD.                                 7



compound must at least contain Fe, Co, B, and at least
one element from each group R and M.
    The relevant claims of the ’651 patent are also di-
rected toward a crystalline structure, except with the
formula of R(Fe,Co)BXAM. Like the relevant claims in
the ’368 patent, here the claims also require the presence
of at least one element from the R and M groups. Howev-
er, the relevant claims of the ’651 patent also require at
least one element from each X and A groups. Groups X
and A consist of the following elements: Group X is
composed of elements S, C, P, and Cu; and Group A is
composed of elements H, Li, Na, K, Be, Sr, Ba, Ag, Zn, N,
F, Se, Te, and Pb. The relevant ’651 patent claims also
include one additional element in group M that is not
present in the relevant ’368 patent claims’ definition of
group M, Si. Thus, to satisfy the relevant claims of
the ’651 patent the compound must at least contain Fe,
Co, B, and at least one element from each group R, X, A,
M; two more elements than is required in the rele-
vant ’368 patent claims. In other words, except for the
slight variance in group M, the only difference between
the relevant claims in the ’368 patent and the ’651 patent
is the addition of two elements, one from each of group X
and A.
     Additionally, in construing the relevant ’368 patent
claims, we concur with the Board that, because the claims
were drafted in the “consisting essentially of” format, the
scope of the claims can include those additional elements
which do not materially affect the basic and novel charac-
teristics of the claimed invention as specified in the ’368
patent specification. See Application of Herz, 537 F.2d
549, 551 (CCPA 1976) (“[I]n construing the phrase ‘con-
sisting essentially of’ in appellants’ claims, it is necessary
and proper to determine whether their specification
reasonably supports a construction that would include
additives . . . .”).
8                                  IN RE: HITACHI METALS, LTD.




     The Board correctly turned its attention to the specifi-
cation, which explicitly states that various starting mate-
rials may include impurities that will be present in the
finished product, in determining what elements are
included in the claims. For example, the specification
states that iron may include carbon, phosphorous, man-
ganese, sulfur, copper, chromium, nickel, copper, and
aluminum as impurities, boron may include carbon as an
impurity, and neodymium may include fluorine as an
impurity. ’368 patent col. 9 ll. 15-27. Furthermore, the
specification gives no indication that the starting ele-
ments must undergo any treatment to remove said impu-
rities. Additionally, the specification makes clear that the
composition claimed in the ’368 patent need not use pure
starting elements. For example, the ’368 patent’s specifi-
cation states that tetragonal systems “are stable when
they contain up to 1% of H, Li, Na, K, Be, Sr, Ba, Ag, Zn,
N, F, Se, Te, Pb, or the like.” Id. at col. 23 ll. 28-31. It is
notable that these elements are not claimed in the ’368
patent, but are instead members of group A as defined by
the relevant ’651 patent claims. Thus, we conclude that
the Board had a sufficient basis for finding that the
relevant ’368 patent claims included carbon, phosphorous,
manganese, sulfur, copper, chromium, nickel, copper, and
aluminum.
    We now turn to the second prong of the test for obvi-
ousness-type double patenting, determining “whether the
differences in subject matter between the two claims
render the claims patentably distinct.” Eli Lilly, 251 F.3d
at 968. We conclude that the Board properly held that
the ’651 claims were obvious variations of the ’368 claims.
As discussed above, while the relevant ’368 patent claims
do not explicitly include elements from groups X and A,
this court construes the claims to include the impurities
carbon, phosphorous, copper, and fluorine.          Carbon,
phosphorous, and copper are all members of the ’651
patent’s X group and fluorine is a member of the ’651
IN RE: HITACHI METALS, LTD.                              9



patent’s A group. Thus, the relevant claims of the ’368
patent include at least one claimed compound that would
satisfy claim 1 of the ’651 patent, as at least a single
element of groups R, X, A, and M are present in the
relevant ’368 patent claims’ compounds. In other words,
by making, for example, the compound claimed in claim
13 of the ’368 patent, the compound would include not
only Fe, Co, B and an element of each group M and R—as
required by claim 13—but would also include impurities
that are defined as belonging to the ’651 patent claims’ X
and A groups. Therefore, as the relevant ’651 patent
claims at issue are not patentably distinct from the rele-
vant ’368 patent claims, the claims are invalid.
   We have reviewed Appellants’ remaining arguments
and find them unpersuasive.
                        CONCLUSION
    For the reasons stated above, we affirm the judgment
of the Patent Trial and Appeal Board rejecting claims 1, 2,
6, 7, and 15-24 of Hitachi’s U.S. Patent No. 5,645,651 in
ex parte reexamination Control No. 90/010,759 for obvi-
ousness-type double patenting over claims 1, 3, 13, 16, 29
and 34 of U.S. Patent No. 4,792,368.
                       AFFIRMED
