To read, or not to read an unrecited limitation into a patent claim, that is a question
| July 26, 2018
Blackbird Tech LLC v. ELB Electronics, Inc.
July 16, 2018
Before Prost, Moore and Reyna. Opinion by Moore. Dissenting opinion by Reyna.
Summary
Finding no suggestion in the specification or prosecution history that the disputed unrecited limitation is important in any way that would merit reading it into the patent claim in dispute, the Federal Circuit vacated district court’s entry of judgment of noninfringement based on the contrary claim construction, and remanded the case to the district court for further proceedings. Dissenting opinion expressed totally opposite view on the issue, and affirmed the district court’s judgment.
Details
I. Background
- U.S. Patent No. 7,086,747 (“‘747 patent”)
Blackbird, a non-practicing entity, owns ‘747 patent, which is directed to energy efficient lighting apparatuses. One embodiment, illustrated in Fig. 5 below, discloses retrofitting an existing light fixture with a more energy efficient lighting apparatus 500 which includes a housing 528 having an attachment surface 530 and illumination surface 532; a circuit board 511 holding a plurality of LEDs 504; and a fastening mechanism 534.
The relevant portion of the specification describes that in “typical operation” the attachment surface 530 is secured to the ballast cover (not shown in Fig. 5) of the existing light fixture (not shown in Fig. 5) through a fastening mechanism 534. ‘747 patent at 9:16–19, 9:36–51 (emphasis added).
Claim 12, the representative of the ‘747 patent, recites as below (numerals in parentheses each indicates a corresponding element in Fig. 5):
12. An energy-efficient lighting apparatus (500) for retrofit with an existing light fixture having a ballast cover (not shown in Fig. 5), comprising:
a housing (528) having an attachment surface (530) and an illumination surface (532);
a plurality of illumination surface holes in the illumination surface;
a circuit board (511) comprising a plurality of light-emitting diodes (504), wherein the circuit board is positioned adjacent the housing so that the plurality of light-emitting diodes protrude through the plurality of illumination surface holes in the illumination surface; and
a fastening mechanism (534) for securing the attachment surface of the lighting apparatus to the illumination surface, wherein the lighting apparatus is coupled to a wall switch and wherein the illumination of the light-emitting diodes is controllable based upon the position of the wall switch (emphases added).
- The District Court
Blackbird sued ELB Electronics, Inc., et al. (“ELB”) for infringing claim 12 of the ‘747 patent.
In the litigation, the parties disputed the meaning of “attachment surface,” specifically whether the attachment surface must be secured to the ballast cover. Blackbird proposed construing “attachment surface” as “layer of the housing to which the illumination surface is secured,” whereas ELB proposed “layer of the housing that is secured to the ballast cover and to which the illumination surface is secured.” The district court agreed with ELB and construed “attachment surface” as “layer of the housing that is secured to the ballast cover.” Following the claim construction, Blackbird stipulated to noninfringement, and the district court entered judgment in favor of ELB.
Blackbird timely appealed. The sole issue on appeal was whether the “attachment surface” in claim 12 must be secured to the ballast cover of the existing light fixture.
II. The Federal Circuit
- Court Opinion by Judge Moore
The Court reviewed the district court’s claim construction based solely on intrinsic evidence de novo, and interpreted the meaning of the “attachment surface” as “layer of the housing to which the illumination surface is secured,” and concluded that the district court erred in the claim construction. Based on the interpretation, the Court vacated the district court’s entry of judgment of noninfringement and remanded the case for further proceedings. The Court reached the conclusion in view of considerations below.
(a) Claim
The Court pointed out, “[b]y its plain language, claim 12 does not require the attachment surface to be secured to the ballast cover. Claim 12 expressly recites a fastening mechanism for securing the attachment surface to the illumination surface. It does not refer to any other fastening mechanism. It does not require the attachment surface be secured to anything other than the illumination surface.”
As to ELB’s argument that the preamble, “[a]n energy-efficient lighting apparatus for retrofit with an existing light fixture having a ballast cover,” requires reading in the disclosed fastener for the claim to achieve its “retrofit” function, the Court dismissed the argument by holding that the apparatus disclosed in claim 12 is structurally complete as claimed.
(b) Specification
While the Court conceded that the specification discloses an embodiment for an energy efficient lighting apparatus that can be retrofitted on an existing fixture, and that embodiment describes a fastener that connects the ballast cover to the attachment surface, the Court did not agree that this fastener limitation should be imported into the claim. In reasoning that there is no suggestion in the specification that this fastener is important in any way that would merit reading it into claim 12, the Court pointed out that the specification never refers to this run-of-the-mill fastener as the “present invention” or “an essential element” or uses any other language that would cause the ordinarily skilled artisan to believe that this fastening mechanism is an important component of the invention or that it is critical to the invention for any reason.
As to the description of the embodiment in Figure 5 (“in “typical operation” the attachment surface 530 is secured to the ballast cover”), the Court pointed out that the specification explains that the fastening can be achieved by “many different types of fastening mechanisms” including “an adhesive strip” (think tape), “a magnet, clips, screws, etc.” The Court also noted that the specification explains the embodiment in Figure 5 is exemplary and non-limiting. Without any evidence that the fastener is important, essential, or critical to the invention, the Court noted, it should not be read in as a claim limitation.
As to the description of the summary of the invention, the Court appears to have given little weight to it at most with a comment in a footnote, ” [i]n cases where we have held limitations ought to be read in, it was not simply because those limitations appeared in the Summary of the Invention. There was specific language that made clear those limitations were important to the claimed invention. See, e.g., Regents of Univ. of Minn. v. AGA Med. Corp., 717 F.3d 929, 936 (Fed. Cir. 2013) (finding disclosures in the Summary of the Invention limiting where directed to “[t]he present invention”).”
(c) Prosecution History
During prosecution, in agreement with the examiner, the applicant amended claim 12 to delete “ballast cover” and replace it with “illumination surface” “to resolve 112 issues.” That is, the applicant expressly eliminated from the claim a fastening mechanism that secures the attachment surface to the ballast cover and replaced it with a fastening mechanism that secures the attachment surface to the illumination surface. The claim was then allowed.
The Court regarded this prosecution history as possibly the most important reason why the fastener for connecting the attachment surface to the ballast cover disclosed in an embodiment ought not be imported into the claim. The Court noted that no ordinary artisan could read the prosecution history as anything other than eliminating the requirement that a fastening mechanism secures the attachment surface to the ballast cover. No other possible reason was suggested or alleged in this case.
- Dissenting opinion by Judge Reyna
Judge Reyna construed the disputed terms the other way around. He viewed that the intrinsic record fully supports the district court’s construction of attachment surface as being secured to the ballast cover in view of the following considerations.
(a) Claim
A person of ordinary skill would necessarily conclude that the attachment surface is secured to the ballast cover of the existing light fixture given that the only feature of the existing light fixture described in claim 12 is the ballast cover.
(b) Specification
Every single embodiment of the retrofit lighting apparatus in the specification describes securing the attachment surface to the ballast cover of the existing light fixture. In addition, the summary of the invention in the specification expressly discloses retrofitting by securing the attachment surface to the ballast cover likewise in the embodiment disclosed in connection with Figure 5.
The majority’s construction without pointing to anything in the specification describing a retrofit apparatus in which the attachment surface is not secured to the ballast cover opens the door for the ‘747 patent to be subsequently invalidated for failure to satisfy the written description requirement because there is thus no suggestion in the record that such an embodiment was ever contemplated or possessed by the inventor. See Carman Indus., Inc. v. Wahl, 724 F.2d 932, 937 (Fed. Cir. 1983) (“Claims should be so construed, if possible, as to sustain their validity. If such a construction would result in invalidity of the claims, the appropriate legal conclusion is one of noninfringement, not invalidity.”)
(c) Prosecution History
Referring to the case law that the prosecution history “can often inform the meaning of the claim language by demonstrating how the inventor understood the invention” but “lacks the clarity of the specification and thus is less useful for claim construction purposes,” Phillips, 415 F.3d 1303, 1317 (Fed. Cir. 2005) (en banc), Judge Reyna concluded that the amendment in question is ambiguous as to the scope of the disputed limitation and such ambiguous amendment should not negate the evidence in the specification and the conclusion implicit in the claim language that the attachment surface is secured to the ballast cover.
Note
It appears that neither party raised an issue of applicability of 35 U.S.C. 112, paragraph 6 to the “fastening mechanism for securing the attachment surface of the lighting apparatus to the illumination surface” in claim 12. Also, neither court discussed the issue sua sponte.
It is interesting to see whether the outcome would have been different if any party had raised the issue with reference to the following portion of the specification of the ‘747 patent.
“The attachment surface 530 of the housing 528 includes a fastening mechanism 534. The fastening mechanism 534 performs the function of securing the attachment surface 530 of the housing 528 to the ballast cover. In the illustrated embodiment, the fastening mechanism 534 is an adhesive strip 534 having a protective cover. The protective cover may be easily removed to expose the adhesive strip 534. One side of the adhesive strip 534 may be attached to the attachment surface 530 of the housing 528. The other side of the adhesive strip 534 may be attached to the ballast cover (not shown) to which the lighting apparatus 500 is to be installed. Of course, in alternative embodiments many different types of fastening mechanisms 534 may be used. For example, in some embodiments the fastening mechanism 534 may use a magnet, clips, screws, etc.” (Emphases added).
Takeaway
- A claim should recite limitations both necessary and minimal to define the invention claimed. Limitations beyond this could cause unnecessary dispute in patent enforcement.
- It is important to be aware that characterizing an element in a claim as “important,” “essential,” or “critical to the invention” in specification or during prosecution could lead to disavowal of a certain scope of the claim.
