## Facts

- Illinois Tool Works Inc., through its subsidiary Trident, Inc., sold printing systems that included a patented printhead and ink container, along with unpatented ink.
- Trident sold to original equipment manufacturers under agreements requiring exclusive purchase of Trident ink and prohibiting refilling the patented ink containers with any other ink.
- Independent Ink, Inc. developed and sold ink chemically equivalent to Trident’s ink for use with Trident-compatible systems.
- After Trident brought and lost a patent infringement action, Independent Ink sued alleging illegal tying and monopolization under §§ 1 and 2 of the Sherman Act, and also sought declarations of noninfringement and patent invalidity.
- The district court granted summary judgment for Illinois Tool Works/Trident on the § 1 tying claim, rejecting the contention that a patent alone establishes market power as a matter of law.
- The Federal Circuit reversed on the § 1 claim, concluding it was bound by precedent treating a patent on the tying product as creating a presumption of market power.
- The Supreme Court granted certiorari to decide whether patent-based market-power presumptions apply in antitrust tying cases.

## Issues

1. In a Sherman Act § 1 tying claim, must a plaintiff prove market power in the tying product, or may a court presume market power from the fact that the tying product is patented?
2. Whether earlier tying precedents justify a patent-based presumption of market power in modern antitrust analysis.

## Decision

- The Court unanimously reversed the Federal Circuit and remanded.
- The Court held that a patent does not necessarily confer market power for purposes of a tying claim.
- In all tying cases, including those involving patented tying products, the plaintiff must prove that the defendant has market power in the tying product; no presumption arises from patent status alone.

## Legal Principles

- A Sherman Act § 1 tying claim requires proof of market power in the tying product; patent ownership does not substitute for that proof.
- The historical assumption that patents imply market power originated in patent misuse doctrine and should not control antitrust tying analysis.
- Modern tying doctrine requires evidence-based assessment of market power rather than categorical presumptions tied to the existence of a patent.
- Congressional treatment of patent misuse, including statutory reforms rejecting automatic patent-tying misuse, supports rejecting a patent-based market-power presumption in antitrust.

## Conclusion

The Court eliminated any antitrust presumption that a patented tying product confers market power, requiring plaintiffs alleging illegal tying under Sherman Act § 1 to prove market power in the tying product with evidence rather than relying on patent status.


Illinois Tool Works Inc. v. Independent Ink, Inc., 547 U.S. 28 (2006)