Mettler-Toledo, Inc. v. B-Tek Scales, LLC

• Decision Date: 08 February 2012
• Docket Number: 2011–1200.,Nos. 2011–1173,s. 2011–1173
• Citation: 101 U.S.P.Q.2d 1619,671 F.3d 1291
• Parties: METTLER–TOLEDO, INC., Plaintiff–Appellant, v. B–TEK SCALES, LLC, Defendant–Cross Appellant.
• Court: U.S. Court of Appeals — Federal Circuit

101 U.S.P.Q.2d 1619

671 F.3d 1291

METTLER–TOLEDO, INC., Plaintiff–Appellant,

v.B–TEK SCALES, LLC, Defendant–Cross Appellant.

Nos. 2011–1173

2011–1200.

United States Court of Appeals, Federal Circuit.

Feb. 8, 2012.

James L. Kwak, Standley Law Group, LLP, of Dublin, OH, argued for plaintiff-appellant. With him on the brief were Jeffrey S. Standley and F. Michael Speed, Jr.

Richard H. Tilghman, IV, Ungaretti & Harris, LLP, of Chicago, IL, argued for defendant-cross appellant. With him on the brief were F. Thomas Hecht, Richard C. Himelhoch and Lisa C. Sullivan.

Before BRYSON, MOORE, and REYNA, Circuit Judges.

MOORE, Circuit Judge.

Mettler–Toledo, Inc. (Mettler) filed suit accusing B–Tek Scales, LLC (B–Tek) of infringing claims of U.S. patent nos. 4,815,547 ('547 patent) and 4,804,052 ('052 patent). After the district court construed the claims, a jury determined that the claims of the '547 patent were not infringed and that the claims of the '052 patent were both not infringed and invalid. Mettler appeals the district court's denial of Judgment as a Matter of Law (JMOL) for each of these determinations. Because the district court correctly construed the claims of the '547 patent and because substantial evidence supports the jury's verdict of invalidity of the '052 patent, we affirm.

Cross–Appellant B–Tek appeals the district court's denial of sanctions for alleged withholding and destruction of relevant documents. Because the district court did not abuse its discretion in determining that the documents were not highly relevant and that there was little harm to B–Tek, we affirm.

Background

The '547 and '052 patents relate to technology for weighing objects, such as large commercial trucks. The '547 patent describes an individual load cell that is one of several cells used in a scale. The cell produces an electrical signal in response to being deformed by an external force such as an object to be weighed. The '052 patent describes a system and method for measuring the weight of moveable objects on a scale. Specifically, the patent discloses a system for correcting weight measurements based on the location of objects on a scale. For example, an object placed at one end of a scale may exert more pressure on the weight sensors positioned at that end than an identical object placed in the center. The '052 patent describes correcting for this load position so that the same total weight will be determined regardless of the placement of the object.

Mettler sued B–Tek alleging infringement of certain claims of the '547 and ' 052 patents. The district court construed the claims and the case proceeded to trial where the jury found that B–Tek did not infringe any of the asserted claims of the '547 and '052 patents. The jury also determined that the asserted claims of the '052 patent would have been obvious. Mettler filed a motion for JMOL on both the infringement and invalidity issues, which the court denied. Mettler appeals the district court's denial of its motion for JMOL for both patents. B–Tek cross appeals the district court's denial of sanctions. We have jurisdiction under 28 U.S.C. § 1295(a)(1).

Discussion

We apply the law of the regional circuit when reviewing a denial of JMOL. Union Carbide Chems. & Plastics Tech. Corp. v. Shell Oil Co., 425 F.3d 1366, 1372 (Fed.Cir.2005); WMS Gaming, Inc. v. Int'l Game Tech., 184 F.3d 1339, 1361 (Fed.Cir.1999). In the Fifth Circuit, JMOL is appropriate if the facts and inferences point so strongly and overwhelmingly in favor of one party that a reasonable jury could not have concluded otherwise. Armendariz v. Pinkerton Tobacco Co., 58 F.3d 144, 148 (5th Cir.1995) (citation omitted). “There must be a conflict in substantial evidence to create a jury question.” Id. We have interpreted this standard to mean that a jury's determination must be supported by substantial evidence. ACCO Brands, Inc. v. ABA Locks Mfrs. Co., 501 F.3d 1307, 1312–13 (Fed.Cir.2007). We review claim construction de novo. Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1455–56 (Fed.Cir.1998) (en banc). The words of a claim are generally given their ordinary and customary meaning as understood by a person of ordinary skill in the art when read in the context of the specification and prosecution history. See Phillips v. AWH Corp., 415 F.3d 1303, 1313 (Fed.Cir.2005) (en banc).

I. '547 Patent

The '547 patent describes a load cell for measuring a force. '547 patent col.1 ll.51–53. The cell utilizes a counterforce attached to a circuit board illustrated in figure 5:

Image 1 (6.94" X 3.77") Available for Offline Print The circuit includes strain gauges 75, 76, 79 and 80 which, via a bridge circuit, create an analog electrical signal related to an object's weight. Id. col.4 ll.62–66. This analog signal is converted to a digital signal by “multiple slope integrating analog-to-digital (A/D) converter 100.” Id. col.5 ll.1–2. This digital signal is then sent to microprocessor 105. Id. col.5 ll.9–15. Claim 1 is illustrative of the asserted claims:

Weighing apparatus comprising a counterforce,

transducer means mounted on said counterforce, circuit means associated with said counterforce, said circuit means being responsive to external control and including means for producing digital representations of loads applied to said counterforce,

means for applying at least one correction factor to said digital representations and means for transmitting said digital representations,

means providing a sealed enclosure for said transducer means and said circuit means,

means providing a path through said enclosure means for external communication with said circuit means.

The district court construed a number of the means-plus-function claim terms including the terms in dispute: “circuit means associated with said counterforce, said circuit means being responsive to external control,” “means for producing digital representations of loads applied to said counterforce,” and “means for transmitting said digital representations.” It held that, for each of these terms, the associated structure in the specification includes the multiple slope integrating A/D converter, and equivalents thereof. For example, for the term “means for producing digital representations of loads applied to said counterforce,” the district court held that the corresponding structure was “a multiple slope integrating analog-to-digital (A/D) converter, and equivalents thereof.” Mettler–Toledo, Inc. v. Fairbanks Scales Inc., 551 F.Supp.2d 576, 598 (E.D.Tex.2008).

In the accused products, the A/D converter is a delta-sigma A/D converter. The jury determined that the accused products did not infringe either literally or under the doctrine of equivalents. In its JMOL motion, Mettler argued that the delta-sigma A/D converter is equivalent to the multiple slope integrating A/D converter. The district court held that substantial evidence supported the jury's verdict that they were not equivalent pointing to trial testimony by B–Tek's expert and a corporate representative from another defendant that there are substantial differences between the two types of converters.

On appeal, Mettler limits its arguments to a single claim construction issue: whether the district court improperly construed the relevant claim terms to require a multiple slope integrating A/D converter rather than any generic A/D converter. Mettler argues that the district court erred by importing the structure of only the preferred embodiment or best mode of the disclosure into the claim. It contends that A/D converters are well-known in the art and that there was no reason to limit the structure to only the multiple slope integrating A/D converter. It further points to figure 5 that illustrates an “Analog to Digital Converter 100”. It argues that this shows that the specification discloses generic A/D converters as well as the more specific multiple slope integrating embodiment. Mettler contends that the Abstract, by mentioning a generic A/D converter, supports its broad construction. Finally, Mettler points out that the district court applied a different construction for the '052 patent, holding that a generic A/D converter is included in the claim term's construction. It argues that the two patent specifications are very similar and both disclose a generic A/D converter linked to the claimed functions.

Citing Medical Instrumentation & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1211 (Fed.Cir.2003), B–Tek responds that the patent never links a generic A/D converter to the claimed functions. It points out that the A/D converter shown in figure 5 is only referred to in the specification as “multiple slope integrating analog-to-digital (A/D) converter 100.” '547 patent col.5 ll.1–2. It argues that every mention of a converter in the specification refers back to this specific type of converter.

We agree with the district court that the appropriate structure for the disputed means-plus-function claim elements in the '547 patent is the multiple slope integrating A/D converter and equivalents thereof. Our case law is clear that a means-plus-function claim limitation is limited to the structures disclosed in the specification and equivalents. Med. Instrumentation & Diagnostics, 344 F.3d at 1210. A court must look to the specification to determine the structures that correspond to the claimed function. “[S]tructure disclosed in the specification is ‘corresponding’ structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.” B. Braun Med. Inc. v. Abbott Labs., 124 F.3d 1419, 1424 (Fed.Cir.1997). If a patentee chooses to disclose a single embodiment, then any means-plus-function claim limitation will be limited to the single disclosed structure and equivalents thereof. See Nomos Corp. v. Brainlab U.S.A., Inc., 357 F.3d 1364, 1368 (Fed.Cir.2004).

The '547 patent discloses a single embodiment for the claimed invention...