Iijima Taizo was born on September 24, 1925, graduated from the Depertment of Electrical Engineering, Tokyo Institute of Technology, jn 1948 and joined the Electro-Technical Lab. at once. He had engaged in research on the theory of electro-magnetic field under the guidance of Goto M., a basic director of the Lab. He was especially interested in the therory of integral equation and succeeded in obtaining the exact solution for the problem of the electro-magnetic wave radiation from a circular waveguide for the first time in the world by using the theory. The base of his function analytic theoretical research which had come to be developed consistently since then was the one which had been built through this research.

After moving to the electronic division of the same place, he developed the character reader of the first time in our country in relation to the development of the translation machine. This became an opportunity, he determined a serious study on the theory of pattern recognition to be started. It was due to the result of seeing through that the function analytic consideration was indispensable for the elucidation of pattern information. He established a united basic theoretical system concerning the visual pattern recognition in 1965. The elucidation of the fact that the blure of the Gaussian type originally accompanied the image caught by the vision and the construction of the linear feature extraction theory in advance of the world, etc. were included in this theoretical system.

After that, the research and development project of a super-high performance computer was begun by the Ministry of International Trade and Industry. He would aim at the development of an original character reader in the project and succeeded in the research and development of super-high performance OCR "ASPET/71" in 1971 after five years. In the design of this OCR, above-mentioned basic theoretical system and "Multiple Simularity Method" having been newly invented by him played the leading part. This work won the place in which it contributed to rapid development of the OCR technology by the fact that the reading of the low quality character thought to be impossible till then had become possible for the first time. The practical use of the Chinese character reader and the ZIP code reading division machine were large depending on this technology.

In addition, he had handled an original research over many fields afterwards. He is taking an active part as a president of Soken Institute Inc. now though he held the professor of Tokyo Institute of Technology, the professor of Tokyo Engineering University, and the vice-president of Japan Advanced Institute of Science and Technology successively.