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March 14, 2002

Judgment rendered by Tokyo High Court Substantially Invalidating Nichia Corporation's Patent (decided in Toyoda Gosei's favor)

Toyoda Gosei Co., Ltd. ("Toyoda Gosei") (President: Mr. Takashi Matsuura) previously brought a suit before the Tokyo High Court demanding the annulment of the "Trial Decision Rejecting the Demand for Invalidation of Patent (affirming the validity of patent right)" rendered on March 27, 2001 by the Japanese Patent Office concerning the invalidation trial (Heisei-11 Trial No. 35005, Invalidation 2000-35220: Consolidated trial examination) with respect to the following patent, which is one of the patents relating to a gallium nitride-based blue LED which Nichia Corporation owns.
The 18th Civil Division of Tokyo High Court (Judge Nagai as Presiding Judge) rendered judgment today (May 14, 2002) to the effect that the "Trial Decision Rejecting the Demand for Invalidation of Patent" decided by the JPO is annulled (substantially invalidating the patent) and thus, our assertions are justified.

Please note that the subject patent is the sixth infringement case filed by Nichia Corporation against Toyoda Gosei (Tokyo District Court Heisei-10 (wa) No. 28407). We consider that as a result of the Tokyo High Court's judgment rendered this time, Nichia Corporation's claims in the above-mentioned infringement lawsuit should be dismissed immediately.

From the beginning of 2001, Toyoda Gosei has consecutively won three cases in a row in Toyoda Gosei's favor as shown in the following table with respect to the lawsuits brought before the Tokyo High Court demanding the annulment of Trial Decision concerning the validity of Nichia Corporation's patent of a gallium nitride-based blue LED in dispute between Toyoda Gosei and Nichia Corporation.

  Nichia Corporation's Patent
Patent No.
Patent No.
Patent No.
JPO's decision
(Date of decision)
(June 16, 2000)
(December 6, 1999)
(March 27, 2001)

Tokyo High Court 
(Date of Judgment)

(June 13, 2001)
(October 2, 2001)
(May 14, 2002)


1. Case No.
  Heisei-13 (Gyo-ke) No. 172
2. Subject Patent
(1) By an metalorganic chemical vapor deposition, and
(2) via the buffer layer caused to grow at the temperatures lower than those of the GaN layer subsequently caused to grow,
(3) an InGaN layer is caused to grow by the metalorganic chemical vapor deposition identical with that mentioned above by using gallium source gas, indium source gas and nitride source gas as raw material gases onto said GaN layer grown at temperatures higher than those of the buffer layer, and
(4) said growing method of InGaN semiconductor has the above features.
3. Grounds for taking the action demanding annulment of trial decision

[Content of JPO's trial decision rejecting the demand for invalidation of patent]:

Although there exists a publicly known reference that refers to causing an InGaN layer to grow on a GaN layer, it is not easy to combine a low temperature buffer layer therewith. In addition, the subject invention is not identical with the publicly known reference, nor is it possible to easily think of the invention from other publicly known references.

[Assertion by Toyoda Gosei]

The Japanese Patent Office misjudged the novelty and inventive step in the invention, and therefore, the patent is invalid.

4. Judgment of Tokyo High Court
  The subject invention could easily be thought of by persons skilled in the art based on the publications that suggest the layer constitution comprising a substrate / a first buffer layer /a GaN layer / a GaInN layer, and based on the well-known technology concerning the GaN layer caused to grow on the buffer layer grown at low temperatures. In addition, the fact that those with constitution comprising a Sapphire substrate / a low-temperature growth AIN buffer layer / a GaN layer / an InGaN layer had already been manufactured by Mr. Takahiro Kozawa enrolled in the Graduate School of Engineering, Nagoya University (Note: Mr. Kozawa later obtained Doctorate in Engineering) in or around 1987 (Note: approximately 5 years before the application for the subject patent) shows the technical standard at that time and this is one of the circumstances enabling presumption that the subject invention could have been thought of easily based on the disclosure of the above-mentioned publications.