A “Teaching Away” Argument Must be Commensurate in Scope with the Claims
| October 17, 2017
Idemitsu Kosan Co., Ltd. v. SFC Co. Ltd.
September 15, 2017
Before Prost, O’Malley and Chen. Opinion by O’Malley.
Summary:
This case is an appeal from an inter partes review of Idemitsu Kosan Co., Ltd’s (“Idemitsu”) U.S. Patent No. 8,334,648 (“the ‘648 patent”) brought by SFC Co. Ltd. (“SFC”). Idemitsu argued on appeal that the Patent Trial and Appeal Board (“PTAB”) did not explain why a skilled artisan would have been led to use the claimed combination of compounds from the teachings of the prior art reference Arakane given that Arakane limits its combination of compounds to combinations satisfying a special relationship. The CAFC agreed with the PTAB in holding that the Arakane reference teaches compounds (including the claimed compounds among others) that when combined, produce a light emitting layer, regardless of the special relationship. The CAFC further held that “evidence concerning whether the prior art teaches away from a given invention must relate to and be commensurate in scope with the ultimate claims at issue.” In this case, the CAFC said that it is not particularly important that Arakane teaches that combinations of compounds not satisfying the special relationship result in poor performance because the claims at issue do not include limitations with respect to performance.
Details:
Idemitsu’s ‘648 patent is to an “Organic Electroluminescence Device and Organic Light Emitting Medium.” Claim 1 is provided below:
1. An electroluminescence device comprising a pair of electrodes and a layer of an organic light emitting medium disposed between the pair of electrodes, wherein the layer of an organic light emitting medium is present as a light emitting layer and comprises:
(A) an arylamine compound represented by formula V:
wherein X3 is a substituted or unsubstituted pyrene residue,
Ar5 and Ar6 each independently represent a substituted or unsubstituted monovalent aromatic group having 6 to 40 carbon atoms, and
p represents an integer of 1 to 4; and
(B) at least one compound selected from the group consisting of anthracene derivatives and spirofluorene derivatives, wherein
said anthracene derivatives are represented by formula I:
wherein A1 and A2 may be the same or different and each independently represent a substituted or unsubstituted monophenylanthryl group or a substituted or unsubstituted diphenylanthryl group, and L represents a single bond or a divalent bonding group, and by formula II:
wherein An represents a substituted or unsubstituted divalent anthracene residue, A3 and A4 may be the same or different and each independently represent a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, at least one of A3 and A4 represents a substituted or unsubstituted monovalent condensed aromatic ring group or a substituted or unsubstituted aryl group having 10 or more carbon atoms; and
said spirofluorene derivatives are represented by formula III:
wherein Ar1 represents a substituted or unsubstituted spirofluorene residue, A5 to A8 each independently represent a substituted or unsubstituted aryl group having 6 to 40 carbon atoms;
provided that the organic light emitting medium does not include a styryl aryl compound.
SFC petitioned for an inter partes review (IPR) of the ‘648 patent. The Patent Trial and Appeal Board (“PTAB”) instituted review of the claims on the grounds of obviousness based on a single reference to Arakane (WO 02/052904). The Arakane reference is assigned to Idemitsu and teaches an organic electroluminescence device. Arakane discloses:
The present invention provides an organic electroluminescence device including a pair of electrodes and an organic light emitting medium layer interposed between the electrodes wherein the organic light emitting medium layer has a mixture layer containing (A) at least one hole transporting [“HT”] compound and (B) at least one electron transporting [“ET”] compound and the energy gap Eg1 of the [HT] compound and the energy gap Eg2 of the [ET] compound satisfy the relation Eg1<Eg2.
Among the HT compounds, Arakane discloses a compound corresponding to formula V of claim 1. And among ET compounds, Arakane discloses compounds corresponding to compounds of formulas I and II of claim 1, respectively.
The PTAB held the claims of the ‘648 patent to be obvious over Arakane. Specifically, the PTAB held that Arakane’s HT compound corresponds with the formula V compound of claim 1; that Arakane’s ET compounds correspond with compounds of formulas (I) and (II) of claim 1; and that Arakane teaches that a light emitting layer can be formed by combining an HT and ET compound. The PTAB stated that the claimed invention “is the combination of recited components in a light emitting layer” and that “Arakane’s disclosure would have informed an ordinary artisan that combining components (A) and (B) would produce a light emitting layer.” The PTAB further stated that the obviousness of the combination “does not depend on whether the resulting light emitting layer would satisfy Arakane’s energy gap relationship.”
Idemitsu argued on appeal that the PTAB made no finding with respect to the energy gap relationship taught in Arakane, i.e., that the energy gap of the HT compound must be less than the energy gap of the ET compound. The CAFC stated that the PTAB correctly found that Arakane suggests combinations of HT and ET compounds that produce a light emitting layer, regardless of their energy gap relation.
Idemitsu also argued that this was raised too late because it was not in SFC’s petition or in the PTAB’s institution decision. However, the CAFC stated that Idemitsu is the party that implicitly raised the argument by arguing that SFC failed to explain why a skilled artisan would have been led to use the combination of HT and ET compounds given that Arakane limits the combination of compounds to combinations satisfying the energy gap relationship. In its counterargument, SFC argued that Arakane does not teach away from the claimed combination despite the absence of demonstrating that the combination would possess the preferred energy gap relationship. The CAFC stated that SFC’s statements were “the by-product of one party necessarily getting the last word,” and thus the argument was not raised too late.
The CAFC also noted that Idemitsu provided no supporting evidence for its position that Arakane teaches away from non-energy gap HT/ET combinations, and that SFC was not required to rebut attorney argument with expert testimony.
The CAFC further stated that Idemitsu’s argument regarding “teaching away” is of questionable relevance. The CAFC explained that “evidence concerning whether the prior art teaches away from a given invention must relate to and be commensurate in scope with the ultimate claims at issue.” The CAFC also included the following passage from In re Zhang, 654 F. App’x 490 (Fed. Cir. 2016): “While a prior art reference may indicate that a particular combination is undesirable for its own purposes, the reference can nevertheless teach that combination if it remains suitable for the claimed invention.” The claims at issue do not include limitations with respect to performance characteristics. And Arakane teaches that the only drawback of not satisfying the energy gap relationship is poor performance. Thus, the CAFC concluded that it is of substantially reduced importance that the non-energy-gap HT/ET combinations result in poor performance.
Take Away
As a patent applicant or patent owner, when arguing that a reference teaches away from a claimed invention to demonstrate non-obviousness, you should try to explain why the reference teaches unsuitability of the claimed invention. Relying solely on a teaching of undesirability in the prior art may not be enough to demonstrate a teaching away from the claimed invention.
This case also emphasizes the importance of supporting arguments with expert declarations in inter partes reviews. Idemitsu did not provide evidence supporting a teaching away argument. Thus, SFC and the PTAB could rely solely on the text of the reference.
