The principles guiding construction of a patent are not significantly different from the principles applicable to the construction of any other written instrument. The relevant state of knowledge is that obtaining at the time of the publication of the specification. The construction of a patent is not to be derived from the alleged infringement: ‘as if we had to construe it before the defendant was born’.
Lord Esher MR said: ‘Now as to the law of the case, – Here is a patent, and an alleged infringement. What is the course that the Court ought to take? In my opinion it is perfectly plain that the first thing that the Court must do is to construe the Specification. How can you consider at all the question whether what is alleged is an infringement of the patent until you have made up your mind what is the true construction of the Specification.’
As to construction, he said: ‘Now what is the very first canon of construction of all written business documents? Why, that the Court ought to construe them the day after they were published. That is the first. Therefore in construing this patent, one has no right to do what Mr Moulton so often invited us to do, by considering what the Defendant has done. I adjure that altogether, and I say we are bound to construe the patent as if we had to construe it before the Defendant was born, if the patent was before that time.’
Judges:
Lord Esher MR
Citations:
(1894) 11 RPC 519
Intellectual Property
Updated: 06 May 2022; Ref: scu.442713