The court noted that the 13 past decisions did not raise objections to the right of a defendant to counterclaim and revoke a patent on the grounds that it was invalid.
"With due respect and deference to those cases, the fact that there is a practice does not provide a basis to establish jurisdiction as a matter of law. Nor can practice trump law," said Justice George Wei in judgment grounds issued on Thursday.
Sun Electric, which sells solar energy to consumers here, had sued a holding company for a licensed electricity retailer and developer of rooftop photovoltaic systems.
Sun claimed the company, Sunseap, had breached Sun's patent, which was for a power grid system and a method of determining power consumption at building connections in the system.
Sunseap denied the allegations and, among other things, made a counterclaim to have the patent revoked.
Sun Electric then sought to strike out Sunseap's bid to revoke the patent, but failed before a High Court assistant registrar.
Through a team of lawyers led by M. Ravindran, the company then appealed to the High Court in June.
Mr Ravindran argued that the right to apply to revoke patents was confined to the Registrar of Patents and Sunseap could not start revocation proceedings in the High Court, not even by a counterclaim.
But defence lawyer Lau Kok Keng cited past cases in which such proceedings to revoke a patent had been brought to the High Court by counterclaim, and noted that academic opinion also supported such moves.
Justice Wei said the cases referred "implicitly suggest" the High Court may hear such cases but "it does not appear that this question was ever directly raised, contested or ruled upon in any of the cases. It follows that these decisions cannot be treated as precedents to determine the question of law at hand."
In his 81-page judgment grounds, Justice Wei analysed the relevant provisions of the Patents Act and found the High Court did not possess jurisdiction to revoke a patent, or by way of a counterclaim.
The judge allowed Sun Electric's appeal to strike out the bid by Sunseap to revoke its patent.
Justice Wei acknowledged the decision would draw public interest and be of concern, adding that there was much to be said to reconsider anew, at an appropriate time, the court's jurisdiction and patent procedures by the relevant law reform body and Parliament. - Vijayan, Straits Times, Singapore