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Japanese patent and utility model recognition guide


The following is a vague recognition guide to Japanese patents and utility models. Japanese patents on J-PlatPat and Espacenet are not transcribed, and the documents are scanned in fairly low resolution 1 bpp (pure black and white) which collectively results in extensive damage to the text. English text remains legible as the Latin alphabet is low in detail, but kanji are both highly detailed and absurdly high in number, making recognition extremely hard. It does not matter whether you use manual or automated radical breakdown or Google handwriting recognition: some characters are impossible to transcribe unless you know Japanese. Even kana, as simple as they look, are fraught with confusing typographical variations.

This page was originally created to ease the pain by indicating which metadata fields were worth even trying to transcribe (e.g. applicant, name of invention) but it has been extended to cover additional concepts and information.

This page was created solely for my own reference (since I can neither speak nor read Japanese), but I have extended it with some additional information that may prove useful. It is intentionally not a complete or comprehensive guide.

Field overview

Japanese format

Field no. Legend Field purpose
1 考案の名称 Name of invention

INID format

Many patents use INID codes. Although these are internationally agreed, US and Japanese patents do not use all the same fields. For example, Japanese patents use fields 72 and 71 for applicant and inventor, while US patents use 75 and 73. US patents use field 10 for the patent number, and Japanese patents use field 11.

Field no. Legend Field purpose
11 Various Document number (the legends overlap with the values of field 12); patent numbers may be prefixed with “特開”, e.g. 特開平4-220915 (Japanese patent H04-220915, where 平4 is Heisei 4 or 1992 — see dates below), while utility model numbers may be prefixed with “実公”, e.g. 実公平6-14373 (Japanese utility model H06-15373)
12 Document type (see document types below)
19 “office or organization publishing the document”; here, “日本国特許庁” = Japanese Patent Office
21 実願 or 出願番号 Application number
22 出願 or 出願日 Application date or filing date (see dates below)
43 公開 Publication date
51 Int.Cl. International classification
54 考案の名称 or 発明の名称 Name of invention
57 要約 Summary (abstract)
71 出願人 Applicant
72 考案者 Inventor

Document types

In Japan there are utility models in addition to patents. There are also lots of different classification states for the documents. I do not pretend to understand any of this! For me it is simply a matter of being sure to not call a utility model a patent, and vice versa! Patent processes in Japan and Germany seem to be the most complicated.

Japanese patent numbers take the form of the year (in era format) followed by the serial number for that year, followed lastly by the suffix. The same numeric code can represent more than one document depending on the suffix, and this gets very confusing when trying to locate patents and utility models from J-PlatPat on Google Patents and Espacenet.

The translations below are from Google and may not be precisely correct.

Japanese Field Suffix English
実用新案出願公開 11 Utility model application publication
実用新案出願公告 11 Utility model application announcement
実用新案出願公告番号 11 Utility model application notice number
実用新案公報 12 Y2 Utility model bulletin
特許出願公開 11 Patent application publication
特許出願公開番号 11 Patent application publication number
公開特許公報 12 A Published patent publication
公開実用新案公報 12 U Published utility model


Japanese dates are written in the order year, month, day. For example, the Gregorian date 25th of April 1981 could be written as any of the following:

Two-digit Gregorian years may be preceded with an apostrophe for clarity. On Alps batch labels where the ink has faded, it can be hard to determine whether a year such as “01” means 平成1 (1989) or 2001, although Alps appear to use Gregorian years on their rubber stamps. Leading zeroes for dot-notation are unverified; in one case (an Alps date stamp from 1987) the day has a leading zero but the month does not.


For dates outside of the range 1960–2000, see Japanese Date Comparison Chart. Dates that interest us will begin “昭和” or simply “昭” for the Showa era (1927–1989) and “平成” for the Heisei era (1989 onwards, where 昭和64 = 平成1 = 1989). Patent numbers begin with the year in Japanese era format, for example a patent from 1988—Showa 63—has a number beginning “昭和63…”. In the Latin alphabet, “昭和” in patent numbers is converted to “S”, giving a patent number beginning “S63…”. Likewise, patents from the Heisei era have “平成” converted to “H”, so a 1994 patent number will begin “平成04” in Japanese, and “H04…” in the Latin alphabet.

Latin Japanese Gregorian
Showa 35 S35 昭和35 昭35 1960
Showa 36 S36 昭和36 昭36 1961
Showa 37 S37 昭和37 昭37 1962
Showa 38 S38 昭和38 昭38 1963
Showa 39 S39 昭和39 昭39 1964
Showa 40 S40 昭和40 昭40 1965
Showa 41 S41 昭和41 昭41 1966
Showa 42 S42 昭和42 昭42 1967
Showa 43 S43 昭和43 昭43 1968
Showa 44 S44 昭和44 昭44 1969
Showa 45 S45 昭和45 昭45 1970
Showa 46 S46 昭和46 昭46 1971
Showa 47 S47 昭和47 昭47 1972
Showa 48 S48 昭和48 昭48 1973
Showa 49 S49 昭和49 昭49 1974
Showa 50 S50 昭和50 昭50 1975
Showa 51 S51 昭和51 昭51 1976
Showa 52 S52 昭和52 昭52 1977
Showa 53 S53 昭和53 昭53 1978
Showa 54 S54 昭和54 昭54 1979
Showa 55 S55 昭和55 昭55 1980
Showa 56 S56 昭和56 昭56 1981
Showa 57 S57 昭和57 昭57 1982
Showa 58 S58 昭和58 昭58 1983
Showa 59 S59 昭和59 昭59 1984
Showa 60 S60 昭和60 昭60 1985
Showa 61 S61 昭和61 昭61 1986
Showa 62 S62 昭和62 昭62 1987
Showa 63 S63 昭和63 昭63 1988
Showa 64 S64 昭和64 昭64 1989
Heisei 1 H1 平成1 平1
Heisei 2 H2 平成2 平2 1990
Heisei 3 H3 平成3 平3 1991
Heisei 4 H4 平成4 平4 1992
Heisei 5 H5 平成5 平5 1993
Heisei 6 H6 平成6 平6 1994
Heisei 7 H7 平成7 平7 1995
Heisei 8 H8 平成8 平8 1996
Heisei 9 H9 平成9 平9 1997
Heisei 10 H10 平成10 平10 1998
Heisei 11 H11 平成11 平11 1999
Heisei 12 H12 平成12 平12 2000


See the new translations page.