Infringement of Patent Right

A patent only grants the right to exclude others from making, using or selling your invention. However, unlike trademark, a patent does not guarantee you can implement your invention without infringing the patents of others.

Other patent owners may have dominating or blocking patents which would exclude you from implementing your own invention without a license.

The grant of a subsequent patent raises a presumption of a patentable difference from an earlier patented invention, but there is no presumption that the subsequently granted patent does not infringe the earlier patented invention. (35 U.S.C. 154 Contents and term of patent; 35 U.S.C. 271 Infringement of patent)

The purchaser of a patented product from the patent owner obtains an implied license to use or resell the product free of control. Such authorized sale "exhausts" the patent right.

The patented product, once sold, entitles the buyer to use and resell, but he cannot remake the patented invention. The right to use confers a right to repair but not to reconstruct the patented product. (Adams v. Burke (1873); United States v. Univis Lens Co. (1942))

For direct infringement, whoever without authority makes, uses or sells any patented invention during the term of the patent therefor, infringes the patent. Knowledge of the patent is not an element necessary in establishing direct infringement. You may be an infringer even if you are in total ignorance of the existence of a patent. (35 U.S.C. 271(a) Infringement of patent)

For indirect infringement, whoever actively induces infringement of a patent shall be liable as an infringer. A person manufactured a device capable of an infringing use and sold it with the intent that it should be so used, he infringed the patent even though his device was capable of a noninfringing use. Some degree of knowledge or intent is necessary to constitute indirect infringement. (35 U.S.C. 271(b)(c) Infringement of patent)

There would be infringement by adding steps to a patented process or by imperfect practice of a patented invention, such as weak rather that strong embossing. Imperfect infringement is nonetheless infringement.

Where a manufacturer carried out all but the last steps of the claimed process, the manufacturer’s customer carrying out the last step, the manufacturer would be liable as a direct infringer by in effect treating the manufacturer’s customers as the agents of the manufacturer.

Changing the relative positions or reversal of the parts of a machine does not avert infringement.

Changes of the proportions of the ingredients of a composition of matter without affecting its essential character will not avoid infringement.

An embellishment by technical advances may not escape infringement.

A mere sale of the product made from a patented process does not constitute infringement of the process. The manufacture of a machine which might be used in infringement of patented process does not constitute infringement

It is not an infringement where one element of a claimed combination is missing. Omission of one element or ingredient of a combination covered by any claim of a patent avoids any charge of infringement based on that claim.

For patented composition of matter, adding an ingredient which the patent purposely avoided and substantially changed the character of the composition avoids infringement.

For design patent infringement, if, in the eye of the ordinary observer, giving much attention as a purchaser normally gives, two designs are substantially the same, if the resemblance is such as to deceive such an observer, inducing him to purchase one supposing it to be the other, first one patented is infringed by the others. The essence of design resides, not in the elements individually, nor in their method of arrangement, but in their tout ensemble in that indefinable whole that awakens some sensation in the observer’s mind. (Gorham Co. v. White (1872))

In general, if the words of a claim read on an allegedly infringing device or method, then there is said to be Literal Infringement of that claim.

On the other hand, the Doctrine of Equivalents is an exception to Literal Infringement that patent claims are limited to what they claim. If two devices do the same work in substantially the same way, and accomplish substantially the same result, they are the same even though they differ in name, form or shape. (Winans v. Denmead (1853))

The Doctrine of Equivalents comes into play only when Literal Infringement is not found. The purpose of the Doctrine of Equivalents is to give a patent claim a somewhat broader scope that literally has. It requires that the function performed be assessed rather that the form alone.

An important factor is whether persons reasonably skilled in the art would have known of the interchangeability of an ingredient not contained in the patent with one that was.

The determination of patent infringement is a two-step process. Firstly, we need to derivate the meaning of the patent claims by a studying all relevant patent documents to reach the felt meaning of the claim; and secondly we need to read the claims on the accused product or process to check whether the claimed invention is being made, used, or sold by the alleged infringer.

If the claims read literally on the accused structures, an initial hurdle in the test of Literal Infringement has been cleared. If the claims do not read literally on the accused structures, the Doctrine of Equivalents comes in to play. What is crucial is that the structures must do the same work, in substantially the same way, and accomplish substantially the same result to constitute infringement. (Autogiro Co. of America v. United States (1967))

It is a common practice for a patent applicant to modify or limit the scope of a claim to secure the grant of the patent.

The Doctrine of File Wrapper Estoppel precludes a patent owner from recapturing a claim construction which was surrendered in the patent office to avoid rejection of the patent; and the alleged infringer has acted in reliance upon that surrendered claim. (Hughes Aircraft v. United States (1983))

The Doctrine of File Wrapper Estoppel does not apply where Literal Infringement is established.

The file wrapper indicates the official record of the case within the patent office, including the patent application forms, specifications, drawings, amendments and arguments submitted by the patent applicant.

The alleged infringer should carefully examine all statements, amendments, and so on, filed by the patent owner in the file wrapper, and attempt to show that the patent owner has made the amendments only in order to gain allowance in view of the prior art.

Defenses to allegations of patent infringement include statutory defenses and equitable defenses.

In statutory defenses, the defendant may consider to invalid the patent because it does not meet the requirement of the statute to obtain a patent and thus the patent is not infringed. These include the public use and on sale defenses; or the defense of obviousness.

In equitable defenses, they result in the unenforceability of the patent due to fraud and inequitable conduct, or misuse or delay in filing suit resulting in laches or estoppel.