The Tokyo District Court ruled last week that Ichitaro, a word-processing software produced by software company Justsystem, infringes the patent for a help function, according to a report in The Japan Times Online.
Justsystem is understood to be planning to appeal the ruling and can continue selling the products until a decision is made in a higher court .
Florian Mueller, the campaign manager of an anti-patent Web site, said on Monday that this is a sign of the damage that Europe's Computer Implemented Inventions Directive could cause to companies.
"I'm devastated to read that the survival of Microsoft Word's major competitor in Japan is now in jeopardy," said Mueller. "Let's hope that European politicians will learn this lesson and make sure we don't get the same problems here. With the directive that's proposed by the EU Council, that's exactly what would happen within a very few years."
The European Parliament last week demanded a rethink of the software patent directive, but some campaigners are concerned as the European Commission has not yet decided whether to agree to its demand.