Case report: Toshiba loses semiconductor patent


Victor Lee and Jesse Peng

Japanese company Toshiba owns Taiwanese patent certificate number I315588 (‘588 patent), titled “Semiconductor light emitting device, method of manufacturing the same, and semiconductor light emitting apparatus”.

After sending warning letters to Arima Optoelectronics Corporation (AOC), Toshiba sued the company at the IP Court for patent infringement based on the alleged continuous sale and use of similar LED models. The ‘588 patent was twice amended after being granted, in 2013 and 2014. While the 2013 amendment was approved by the Taiwan Intellectual Property Office (TIPO), the 2014 amendment was pending before the TIPO when the IP Court ruled on the case on September 22, 2015.

AOC, the defendant, responded to Toshiba’s allegations by countering that the amendments went beyond the disclosed subject matter of the ‘588 patent; that the patent claims did not read on its products; that AOC was entitled to prior user rights; and that the ‘588 patent lacked novelty and an inventive step.

AOC first argued that the amendments to the ‘588 patent were invalid because of the illegal expansion beyond the disclosure of the specification. The court ruled otherwise. Although the 2014 amendment was not granted by the TIPO during the trial, it was different to the 2013 counterpart only in its narrowing of the claim scope and clarification of ambiguous claim language. The amendments did not substantially enlarge the scope of claims as granted or go beyond the original disclosure of the specification as filed. The amended claims in the 2014 version were therefore permitted by the court.

Next, before claim construction, the court reasoned that the scope of patent protection described by the examples in the specification only purported to illustrate the embodiments of the given invention. The examples should not be relied on to expand or narrow the scope of the claims as granted; otherwise it is the same as introducing changes or limitations that were originally not included in the claims or would substantially change the scope of patent protection.

Even though the defendant’s products infringed some of the ‘588 patent’s claims, those claims were invalid.


Furthermore, the court emphasised that in order to interpret patent claims, one should recite the claims’ wording literally rather than reading into the specification or abstract, or removing any sections of the claim sentences. If any ambiguity exists or there is unclear use of language, the descriptions and drawings of the invention may be employed as references to determine the definition or meaning that is understandable to a person with ordinary skills in the art.

The claims should be interpreted in an “objective and reasonable” way instead of being personally acknowledged by the applicant. Unless the applicant “acts as his own lexicographer” to specifically reshape a term from its commonly acknowledged meaning to a unique and distinct definition, the term will be identified by a person skilled in the art as having its conventional definition.

After carrying out claim construction and infringement analyses, the court determined that the products fell into seven claims of the permitted 2014 amendment.

The court also rejected the defendant’s prior art defence. Such a defence is admissible when the allegedly infringing products are identical to certain prior art or, if they are not, are the simple combination of certain prior art and the common knowledge in the technical field. In other words, a prior art defence will not be established based on the combination of a plurality of references. Since AOC’s proposed scientific literature concerned semiconductor materials that were not substantially related to the ‘588 patent’s invention of a semiconductor LED, the court held that such a single reference cannot be used to defend the patent claims.

However, the court analysed AOC’s last defence of challenging the patent claims’ validity, finding that the claims in the 2014 amendment were either not novel or lacked inventiveness based on the prior art references. Even though the defendant’s products infringed some of the ‘588 patent’s claims, those claims were invalid. Consequently, Toshiba was not entitled to an enforceable patent right against the defendant’s acts and the court dismissed the case.

Victor Lee is a managing partner and patent attorney at Tsai, Lee & Chen. He can be contacted at:

Jesse Peng is a partner and patent attorney at Tsai, Lee & Chen. He can be contacted at:

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