The Japanese Patent Numbering SystemBy Richard Cushing
The Japanese Patent Numbering System
A Japanese figural ceramic teapot has a thick, clear glaze which is uniformly and heavily crazed suggesting that it is old, but just how old? The seller says the Japanese toy dates to the 1920s but how can you be sure? With increased interest in pre-World War II Japanese ceramics and toys, it is becoming increasingly important to establish accurate dates for Japanese made products. This article introduces the Japanese patent system which helps establish approximate production dates for original Japanese collectibles and can help you avoid recently made reproductions.
The Japanese patent numbering system began in 1885 and has four categories; patent, utility, design and trademark. For antique research purposes, the patent category applies to invented objects and devices. A utility patent is granted for an improvement to an object or device that has already been patented. The design category focuses on the aesthetics of visual appearance of the thing including shape, color and color pattern. Trademarks apply to distinct letters, characters, symbols and logos that can be identified with a particular object or company. A trademark may also be color specific.
Invention patents appear in Table 1. The other three categories of patents appear in Table 2. The number by each year is the beginning number issued for that year. But remember, a patent number (from any country) can not pin point the exact date an object was made. It can only give you the period in which it was made. Why? An object has to have been made after the date the patent number was granted. Patent numbers in most countries remain in force for an average of about 15 years. Therefore, an object with a patent number granted in 1900 could have been made anywhere between 1900 and 1915. Check the patent laws for a particular country to obtain filing dates for specific patents for more precise dating. Also check to see if any extensions were granted which would extend the life of the original patent.
As a case in point for a Japanese example, take the mark shown in Fig. 1. It is marked "PAT NO 63207." The wording "PAT NO" firmly states that this is indeed a patent number and not one of the other three categories of patents (utility, design or trademark). From Table 1, you can find that patent number 63207 was granted in 1928. That means this piece could have been made any time between 1928 and the outbreak of WW II (1928 + 15 years).
If the words "PAT" or "Patent" do not appear with the number, you'll need to decide what other category to look under--design, utility or trademark. Just use the guidelines given in the second paragraph of this article and you shouldn't have any trouble.
To research a Japanese patent number, write to: Japanese Patent Office, 3-4-3 Kasumigaseki, Chiyoda-ku, Tokyo, Japan. Telephone (03) 3581-1101. The author wishes to thank Makoto Ueda, Deputy Executive Director, Japanese External Trade Organization (JETRO) for the primary research information provided. JETRO has branches in most major North American Cities.
Japanese Patent Numbers
|Japanese Utility, Design & Trademark Numbers|
|Arranged by year (left column). The number in the right column shows the first patent number assigned that year.|