JURISDICTION REPORT: INDIA
Understanding Indian patent infringement
By DPS Parmar of LexOrbis
If obtaining a patent is a cumbersome, slow, and tedious process, understanding the infringement of a patent under Indian law and elsewhere is equally enigmatic. Both require specialised knowledge and experience in national patent law and practice.
In India, practice relating to infringement action is developing as more and more infringement cases are being dealt with by specialised IP benches of the high courts.
Two stages: patent infringement analysis
Patent infringement analysis by the courts is a two-step process. The actual process of determination of infringement by the courts involves two stages of analysis by the judge.
The first is the determination of a patented invention. Here the judge determines the scope and meaning of disputed claim terms as a matter of law.
The second step is comparing the properly construed claims to the accused infringement. This involves the determination of “literal infringement” or infringement under the doctrine of equivalents.
The basic purpose of claim analysis is to ensure a balance between fairness to the patentee and giving the public a reasonable degree of certainty as to what those claims cover.
Claim construction
Once a patent is granted, the claims as found in the granted patent as subjected to judicial interpretation to ascertain in true scope and boundary, when the infringement dispute is addressed in the court for adjudication.
Judicial construction of the claim is required in the first place. This poses several other relevant questions such as how to horizontally deal with claim constructions of the district courts and how to vertically address on appeal the constructions of lower courts.
The winning or losing of a case depends primarily on understanding patent boundaries accurately and precisely. The problem with claim construction underlies all legal and factual conclusions of patent validity as well as the risk and actual occurrence of infringement.
There is no statutory limitation on the judges in India or elsewhere to follow a particular approach to claim construction such as purposive or pith and marrow. The decision in Catnic Components v Hill & Smith (1982) was the first case where the rule of purposive construction was applied by the House of Lords.
In this case, Lord Diplock stated, “A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge.”
“The problem with claim construction underlies all legal and factual conclusions of patent validity as well as the risk and actual occurrence of infringement.”
DPS Parmar
Doctrine of equivalents
The next question before the court is to find the insubstantial differences in the accused device/process/invention. This sets in the application of the doctrine of equivalents. How to determine whether a difference is insubstantial is again a tough call.
In the US for example, the court in Warner-Jenkinson v Hilton Davis Chemical (1997) articulated a legal test popularly known as the “triple identity” test. According to this test, the difference between the feature in the accused device and the limitation recited in the patent claim would be insubstantial if the feature in the accused device: 1. Performs substantially the same function 2. In substantially the same way 3. Obtains the same result.
This legal rule was adopted by almost all the patent systems that allow the court to uphold patent infringement allegations even though the infringing device or process does not fall within the literal scope of a patent claim but is equivalent to the claimed invention. US Judge Learned Hand aptly quipped its purpose as being “to temper unsparing logic and prevent an infringer from stealing the benefit of the invention”.
Conclusion
Patent law in India is silent on how to interpret a claim. The term infringement is also not defined in the patent law. In Lallubhai ChakuBhai Jariwala v Chimanlal Chunnilal & Co (1936) it was observed by the Mumbai High Court that the construction of a specification is a matter of law, and it is the court’s job to construct the same.
Since Indian patent law is largely based on UK patent law, Indian courts have been deciding the issue of infringement by applying the two principles of construction, namely textual infringement or infringement of pith and marrow of the invention before the Catnic ruling.
The Catnic ruling overruled all the earlier case law on “mechanical equivalents” and “pith and marrow” and held that a patent specification should be given a “purposive construction” rather than a purely literal one.
It is not that Indian courts are naturally inclined and influenced by the UK precedents; the courts do not hesitate to consider and adopt the US rulings as well to decide the contentious infringement issues. We may find it is mixed a bag of all good precedents elsewhere.
DPS Parmar is a special counsel at LexOrbis and a former technical member (patents) at the erstwhile Intellectual Property Appellate Board. He can be contacted at: dpsparmar@lexorbis.com
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