ITOH International Patent Office

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On the IP scene for almost 60 years, ITOH International Patent Office combines the old and the new: blending vast experience with the knowledge on innovations, such as cutting-edge technology. The entity pursues US filings through its affiliated law firm in the United States, IPUSA. Backed by an army of over 200 experts, which includes South Korean, Chinese and US patent attorneys, ITOH is a prolific filer. The experts are especially skilled in all things cyberspace – from the Internet of things (IoT) to automatic control systems, AI and machine learning. Several experts have passed the Japanese Deep Learning Association G Test and/or the E Test.

Firm Profile

Firm description 

ITOH International Patent Office, established in 1967, specialises in all IP matters. Located in the center of Tokyo, ITOH comprises 280 staff members, including 70 Japanese patent attorneys (three of whom have passed the US Patent Bar exam), an attorney at law (of counsel), four US patent attorneys, three Chinese patent attorneys, one Korean patent attorney, 50 patent engineers and 140 administrative staff members.

In recent years, as Japan has been concentrating on strengthening IP rights to increase the country’s prosperity and as the world’s IP systems have become more harmonised, the global protection of IP has become much more important. In the midst of this change, all members of ITOH continue to strive to offer high-quality and prompt services that completely satisfy our international clients’ needs.


In 2022, as well as in previous years, ITOH was ranked as one of the top three IP firms in terms of number of Japanese patent filings.


Areas of specialism

With respect to patents, ITOH has specialised knowledge in all technical fields, with a focus on artificial intelligence (including machine learning), the Internet of Things, quantum computing, information processing, image processing, fintech, materials-informatics, telecommunications (5G, beyond 5G), digital healthcare, biotechnology, automatic control systems, semiconductors, medical, materials, materials-informatics, chemistry and others.

ITOH also has great expertise in designs and trademarks. One team at the firm handles design issues exclusively, while another handles trademark cases exclusively.


International experience

Since its inception, ITOH has handled not only domestic applications, but also a lot of applications filed by Japan-based clients in other countries across the globe. ITOH’s policy is to have all foreign specifications in English, Chinese and Korean prepared by its in-house patent attorneys and technical specialists, who have extensive knowledge and experience of international patent practices.

ITOH can accurately translate English, Chinese and Korean language specifications into Japanese for filing and prosecuting patent applications in order to secure enforceable patent rights in Japan. ITOH’s patent attorneys and technical specialists are fully versed and knowledgeable in Japanese patent prosecution, enforcement procedures and practices.

With a team of experts who can handle all technical fields, are always up to date on the latest developments in laws and regulations and can draw on knowledge gained through over 50 years of experience, ITOH is equipped to draft and prosecute effective patent applications in order to ensure enforceable patent rights in Japan. As a rule, ITOH conducts interviews with inventors in order to gain a full understanding of their inventions and accurately determine the objectives of clients.

Eight of ITOH’s patent attorneys have previously worked as examiners at the Japanese Patent Office (JPO), giving great insight into the JPO’s practice. In addition, ITOH strategically conducts interviews with JPO examiners so as to avoid file wrapper estoppel issues. Furthermore, another eight of ITOH’s patent attorneys have previously worked in the IP departments of leading Japanese companies such as Sumitomo Heavy Industries, Toshiba, Fujitsu, Hitachi, and others. This in turn gives ITOH the edge in terms of understanding the IP strategies of companies.

Using their extensive experience and thorough legal and technical knowledge gained over the years, the practitioners at ITOH handle not only patent applications, but also trials before the JPO, lawsuits before the IP High Court against JPO appeal decisions, infringement litigation and expert opinions.

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