This slide deals with various doctrine related to Patent infringement with relevant international and national case laws.

1. -Kumar Salva Raghuvanshi

2. Introduction.
• Unlike U.S Patent Law, Indian law does not
address the issue of infringement directly.
• Patent Act, 1970 does not define how to
determine whether a patent has been
infringed or not.
• Dicta of court’s are only guiding principles.
• Vidya Prakash v Shah Charan Singh: Lahore
H.C considered Novelty, Utility and description
as the basis for determining infringement.

3. 1. Literal Infringement
• A patent is infringed if the accused product or
process includes every element exactly as
recited in at least on of its claim.
• Every word of a claim is used in a product,
infringement is said to be literal.
• Thus, claims must be drafted and prosecuted
with great care to minimise the possibility of
competitors who will literally infringe.

4. 1.1 Markman v. Westview Instruments No. 95-26, 64
USLW 4263 (1996) [SC]
Facts:
 Markman combined computer and bar code technology to
minimise lost garments and employee theft during the dry
cleaning process.
 The system developed was capable of monitoring and
reporting the status, location and movement of clothing in
dry cleaning establishment.
 The claimed invention allowed the detection of spurious
additions to the inventory as well as deletions therefrom.
 Defendant system was capable of tracking invoice numbers,
total prices and receivables. {It did not track clothing}
Issue:
 Whether inventory means clothing and/or totals?

5. Markman cont…
• Argument of Markman: Inventory included
clothing and/or totals.
• Argument of Defendant: Inventory meant
clothing.
Jury: Defendant infringed Markman patent.
Trial Court: Not an infringement, because
inventory referred exclusively to articles of
clothing and accused device merely maintained a
listing of invoices, it could not track the location
of individual garments as they moved about the
shop and therefore could not infringe.

6. Markman cont…
Federal Circuit: (on appeal) affirmed the decision of
trial court. The court established two categories of
evidentiary inputs for use in claim interpretation.
I. Intrinsic Evidence: consist of claims, the specification
and prosecution history. Court were required to
consider all intrinsic evidences to determine meaning
of claims.
II. Extrinsic Evidence: Dictionaries and expert tetimony.
Supreme Court: Affirmed the decision of federal court.

7. 2. Doctrine of Pith and Marrow (U.K)
• To constitute infringement, the article must take each
and every one of the essential integers of the claim.
This constitutes pith and marrow principle of
infringement.
• Directed against colourable evasion of patent claim.
• Patent owner has remedy against an alleged infringer
who does not take the letter of the invention but
nevertheless appropriates its substance or “pith and
marrow”.
• Thus, person who borrows the substance of the
patented invention cannot escape the consequences of
infringement by making immaterial variations.

8. 2.1 Catnic Components v. Hill & Smith
[1928] R.P.C. 183 H.L.
Facts:
Claim of the patent was for lintel which was used to
provide structural support over a door or window
opening in a brick wall, the structure of the lintel was
such that the upper plate of the same was supported
lower plate by two rigid supports, one in front and
other extending vertically from the one plate to the
other at the rear. Defendant lintel had a rear support
which was inclined 6 degrees or 8 degrees from the
vertical. The defendant argued that his lintel would
have to be exactly vertical to infringe.

9. Catnic Components v. Hill & Smith
cont…
Trial Court: held there was an infringement
under the "pith and marrow" doctrine.
The Court of Appeal: Overturned the ruling and
held that the "vertical" requirement was an
exact and essential element of the patent.
The House of Lords: Reversed the decision of
the Court of Appeal, finding that there was an
infringement, and affirmed the use of purposive
construction in patent interpretation.

10. Catnic Components v. Hill & Smith
cont…
The House of lords laid 3-Step test:
1. Does the variant have a material effect upon the way the
invention works? If yes, the variant is outside the patent claim. If
no, the next question comes.
2. Would the fact that the variant had not material effect have been
obvious at the date of publication of the patent to reader skilled in
the art. If no, variant is outside the claim. If yes, the third question
needs to be asked.
3. Would the reader skilled in the art nevertheless have understood
from the language of the claim that the patentee intended that
strict compliance with the primary meaning was an essential
requirement of the invention. If yes, the variant is outside the
claim. If no, there is infringement.

11. 2.2 Improver Corp. v. Remington
Consumer Products Ltd. [1990] F.S.R
181
Facts:
The patent covered a depilatory device having a
helical spring driven by motor. The spring when
rotated gripped hairs between its coil and plucked
them from the skin. The alleged infringement
replaced the spring with a rubber rod having slits at
the surface.
Issue:
Whether the slit rubber rod was a
helical spring?

12. Article-69, EPC
Extent of Protection:
(1) The extent of the protection conferred by a European patent or a
European patent application shall be determined by the claims.
Nevertheless, the description and drawings shall be used to interpret
the claims.
(2) For the period up to grant of the European patent, the extent of the
protection conferred by the European patent application shall be
determined by the claims contained in the application as published.
However, the European patent as granted or as amended in
opposition, limitation or revocation proceedings shall determine
retroactively the protection conferred by the application, in so far as
such protection is not thereby extended.

13. Protocol on Article-69, EPC
"Article 69 should not be interpreted in the sense that the
extent of the protection conferred by a European patent is to
be understood as that defined by the strict, literal meaning of
the wording used in the claims, the description and drawings
being employed only for the purpose of resolving an
ambiguity found in the claims. Neither should it be
interpreted in the sense that the claims serve only as a
guideline and that the actual protection conferred may extend
to what, from a consideration of the description and drawings
by a person skilled in the art, the patentee has contemplated.
On the contrary, it is to be interpreted as defining a position
between these extremes which combines a fair protection for
the patentee with a reasonable degree of certainty for third
parties."

14. Improver Corp. v. Remington cont…
Court:
The court held that if the issue was whether a feature embodied in an alleged
infringement which fell outside the primary, literal or a contextual meaning of a
descriptive word or phrase in the claim was nevertheless within the language as
properly interpreted , the court should ask itself the following three questions:
1. Does the variant have a material effect upon the way the invention works? If yes,
the variant is outside the patent claim. If no, the next question comes.
2. Would the fact that the variant had not material effect have been obvious at the
date of publication of the patent to reader skilled in the art? If no, variant is
outside the claim. If yes, the third question needs to be asked.
3. Would the reader skilled in the art nevertheless have understood from the
language of the claim that the patentee intended that strict compliance with the
primary meaning was an essential requirement of the invention. If yes, the
variant is outside the claim. If no, there is infringement.

15. Improver Corp. v. Remington cont…
Held:
Applying the three step test, the court held that
to a PHOSITA reading the claim it would show
that the patentee intended strict compliance
with the component helical spring in its primary
meaning and not in a wide generic sense, as an
essential feature of the invention. On this basis
court held that rubber rod fell outside the
meaning of helical spring and did not infringe.

16. 3. Doctrine of Equivalents (U.S.)
• In the absence of literal infringement, a product
may nevertheless be found to infringe a patented
product if it is found to be its substantial
equivalent.
• Under this doctrine, an accused device infringes a
claim if it “performs substantially the same
function in substantially the same way to obtain
the same result”.
• First applied in the case of Winans v. Denmead.

17. 3.1 Graver Tank & Mfg. v. Linda Air
Products Co. 339 US 605 (1950)
Facts:
 Plaintiff obtained an improvement patent on an electric welding
composition or flux with specifications that were basically a
combination of alkaline earth metal silicate and calcium
fluoride. Defendant began to produce its own composition that
instead used silicates of manganese, not an alkaline earth metal, for
the silicates of magnesium, which is an alkaline earth metal used by
Plaintiff. Plaintiff charged Defendant with infringement. Plaintiff had
mentioned manganese in its specifications, but it was not within the
specific claims of the patent.
 The chemist had testified that magnesium and manganese were
equivalent in the wielding art, and the trial court had properly found
that Lincolnweld and Unionmelt fluxes were in all respects equivalent.
 The United States district court found infringement, and the Court of
Appeals affirmed the infringement claim.

18. Graver Tank & Mfg. v. Linda Air
Products cont…
Court Stated:
1. Unimportant and insubstantial changes and substitution
in the patent will amount infringement.
2. As regards what would constitute equivalents, the court
stated that when the accused product or process
performed substantially the same way to obtain the same
result (triple identity test or function-way-result), an
infringement had occurred under the DOE.
3. Interchangeability of the claimed and substituted
ingredients was an important factor in an equivalency
determination. It has to be proved with views of experts,
learned texts and the disclosure in the prior art.

19. 3.2 Warner-Jenkinson v. Hilton Davis
(516 US 1996)
Facts:
 The plaintiff Hilton Davis Chemical Co., a dye maker, had developed an
"ultrafiltration" process to purify dyes. An amendment to the patent had
specified that a solution used in the process must have a pH level between
6.0 and 9.0. The amendment was filed in order to clarify that this patent
did not overlap with a previously patented process (Booth Patent) that
used a solution with a pH level above 9.0 - however, the plaintiff was
unable to explain why the amendment stated a lower level of 6.0.
The defendant had developed a process using a solution with a pH level of
5.0, which was outside the range of the plaintiff's patent.
 The plaintiff sued for infringement, conceding that the defendant's
process did not literally infringe, but relying on the doctrine of equivalents
to support the claim of infringement. The defendant argued that the
doctrine of equivalents was no longer appropriate for courts to use
because Congress had made some changes to the patent statute after the
Supreme Court's 1950 decision establishing the propriety of using the
doctrine.

20. Warner-Jenkinson v. Hilton Davis
cont….
Issue: Whether the Patent Act, 1952 overruled
the Doctrine of Equivalent?
District Court: No infringement.
Court of Appeal: Affirmed.
“Certiorari was granted”

21. Warner-Jenkinson v. Hilton Davis
cont….
Supreme Court (Reasoning):
• Insubstantial difference infringement.
• Restriction of DOE to variants described in
specifications Rejected (PHOSITA).
• Intention of infringer not relevant.
• Function-way-result Test not only test.
• Prosecution History Flexible & Rebuttable
bar.

22. Warner-Jenkinson v. Hilton Davis
cont….
Supreme Court Held:
1. DOE is not inconsistent with Patent Act.
2. DOE must be applied to individual element of patent claim, not to
invention as whole.
3. Prosecution history estoppel does not apply in every instance
where the patent claim has been amended during application
process, regardless of reasons for change.
4. Patentee’s addition of lower pH during application process did
necessarily preclude application of DOE as to that element.
5. Remand was required to determine whether reason for amending
patent claim to add lower pH limit was sufficient to avoid
prosecution history estoppel.
6. DOE does not require proof of intent.
7. DOE is not limited to equivalent disclosed within patent itself.

23. 3.3 Festo Corp. Shoketsu Kinzoku
Kogyo Kabushiki Co. Ltd, 535 U.S. 722
Background History:
It is a United States Supreme Court decision in the
area of patent law that examined the relationship
between the doctrine of equivalents and the
doctrine of prosecution history estoppel (which
holds that a party who makes a change to a patent
application to accommodate the requirements of
patent law cannot claim indirect infringement of an
element that was narrowed by that change).

24. Festo Corp. Shoketsu Kinzoku cont…
Facts:
Festo Corporation owns two patents for an improved magnetic rod less
cylinder, a piston-driven device that relies on magnets to move objects in a
conveying system. When the patent examiner rejected the initial application
for the first patent because of defects in description, the application was
amended to add the new limitations that the device would contain a pair of
one-way sealing rings and that its outer sleeve would be made of a
magnetisable material. The second patent was also amended during a re-
examination proceeding to add the sealing rings limitation. After Festo began
selling its device, SMC entered the market with a similar device that uses one
two-way sealing ring and a non-magnetizable sleeve. Festo filed suit, claiming
that SMC's device is so similar that it infringes Festo's patents under the
doctrine of equivalents.
Issue:
Does a patentee, by narrowing a claim to obtain a patent, surrender all
equivalents to the amended claim element?

25. Festo Corp. Shoketsu Kinzoku cont…
District Court:
Rejecting SMC's argument that the prosecution history, or the
public record of the patent proceedings, estopped Festo from
saying that SMC's device was similar, the District Court ruled
in Festo's favour.
Court of Appeal:
Ultimately, the en banc Court of Appeals held that the
prosecution history estoppel applied, ruling that estoppel
arises from any amendment that narrows a claim to comply
with the Patent Act. The Court of Appeals also held that, when
estoppel applies, it bars any claim of equivalence for the
element that was amended.
“Certiorari was granted”

26. Festo Corp. Shoketsu Kinzoku cont…
Supreme Court:
1. The Court held that prosecution history estoppel may apply to any claim
amendment made to satisfy the Patent Act's requirements, not just to
amendments made to avoid the prior art, but that estoppel need not bar
suit against every equivalent to the amended claim element.
2. Noting that by amending an application the inventor is deemed to
concede that the patent does not extend as far as the original claim,
3. The Court reasoned that the patentee should bear the burden of
showing that the amendment does not surrender the equivalent in
question.
4. Justice Kennedy wrote that, in cases where an equivalent was
unforeseeable at the time of the application, the patentee could rebut
the presumption that prosecution history estoppel barred a finding of
equivalence by showing that at the time of the amendment one skilled
in the art could not reasonably be expected to have drafted a claim that
would have literally encompassed the alleged equivalent.