F-term (patent law)

This article is about the patent classification used in Japan. For F-term in theoretical physics, see F-term.

In Japanese patent law, F-term is a system for classifying Japanese patent documents according to the technical features of the inventions described in them. It is not a replacement of International Patent Classification (IPC) or other patent classifications; indeed it complements the IPC by providing a means for searching documents from a different viewpoint than that provided by the IPC. A symbol attached to a patent document, indicating that the invention disclosed in the document has a particular technical feature, is also called an F-term.

Just like other patent classifications, F-terms attached to a patent document does not affect the determination of technical scope of the patent right. It serves as an index for searching prior art documents.

The F-term system was developed in 1987 by the Japan Patent Office (JPO) and it is maintained by the same body. The examiners give appropriate F-terms together with IPC to each patent document published by the JPO. However, the F-term system does not have any legal foundation. This contrasts with the IPC authorized by the Strasbourg Agreement of 1971.

The IPC resembles the scientific classification of organisms. Both are gigantic hierarchical classification based on a single viewpoint. In this perspective, the F-term system is like a picture book that presents various views such as "lives in rainforests" or "creatures having wings". In a word, the IPC is systematic while the F-term is intuitive.

The F-term system, developed in 1987, premises employing computers for searching documents. This character is evident from that F-terms did not appear on patent documents printed on paper until 2000. Particularly, it premises the availability of set operation such as union or intersection of patent documents, because all applicable terms are applied on each document. (See the fictional example below.) This contrasts to the original basic idea of the IPC that each patent document falls into one subgroup and documents are stored in book stacks.

Detailed description

The F-term classification system consists of themes and terms.

The coverage area of the IPC is divided into approximately 2900 categories, each of which is called a theme, and each theme spans a range of IPC subgroups. A theme is identified by the title describing the range or the theme-code which consists of five digits allocated uniquely to each theme; for example, a theme spanning IPC range A01K 87/00–87/06 is identified by its title "Fishing rods" and its theme-code 2B019. There exists a theme spanning only one IPC subgroup, such as theme 2F011 "Tape measures" over IPC G01B 3/10.

Each theme has a number of viewpoints and each document is classified repeatedly for each viewpoint in the respective theme. For example, theme 2F011 "Tape measures" has the following four viewpoints: tape measures, housings, driving of tape measures, and accessories.

From each viewpoint, documents are classified into several groups and labeled with a four-digit code called the term or F-term. For example, from viewpoint "tape measures" which focuses on measuring tape itself rather than winding mechanism or housing of tape, all measuring tape documents are classified into eight groups such as AA02 "scales for special applications", AA05 "tapes with cores containing synthetic resins", etc.

All terms concerning a theme are put into a tabular form called an F-term list, which are available online, e.g., 2B019. (Some descriptions of F-terms may seem strange because of incorrect translation from the original Japanese.)

A fictional example

Below is a fictional example of classifying a patent application within the F-term system. The fictional example of a cooking recipe database will be used as this avoids the need for any subject-specific knowledge.

The fictional IPC-style classification of recipes may be as follows:

X99Y 1/00  Dishes
X99Y 1/02  . Meat dishes
X99Y 1/04  . . comprising beef
X99Y 1/06  . . comprising pork
X99Y 1/08  . . comprising lamb
X99Y 1/10  . comprising seafood
X99Y 1/12  . comprising vegetables

This classification of recipes is based on a single viewpoint—the main ingredient of the dishes. Hence we can browse all recipes of meat dishes by selecting recipes labeled X99Y 1/02, X99Y 1/04 and X99Y 1/06, and likewise we can browse all recipes of beef dishes by selecting recipes labeled X99Y 1/04.

However, the system does not allow the user to find all Chinese recipes, or all halaal lamb recipes, because the system is based on a single viewpoint. This is solved by the F-term system by the use of multiple viewpoints.

A fictional F-term classification of recipes may be as follows:

9Z999  Dishes (X99Y 1/00--1/12)
AA    INGREDIENTS
AA11  Meat
AA12  . Beef
AA13  . Pork
AA14  . Lamb
AA21  Seafood
AA22  . Fish
AA31  Vegetable
BB    CUISINE
BB41  Asian
BB42  . Chinese
BB43  . . Cantonese
BB44  . Turkey
BB51  European
BB52  . French
BB53  . Italian
CC    COOKING
CC11  Boiled
CC21  Fried
CC31  Roasted
CC41  Steamed
DD    SPECIAL
DD11  Haraal
DD12  Vegetalian

9Z999 identifies an F-term sheet, or theme. X99Y 1/00--1/12 in the parentheses indicates that the sheet covers the IPC range X99Y 1/00–1/12. AA, BB, or CC identify the different viewpoint of the theme and the combination of two letters and two numbers AA11 etc. identifies features viewed from a specific viewpoint. This 4-symbol construction is known as an F-term. We can therefore find all Chinese recipes by selecting recipes having an F-term of BB42.

Since all applicable F-terms are applied to a given document a boolean-logic search can be used to find combinations of features—for example to find halaal lamb recipes a search can be made for recipes having both AA14 and DD11 F-terms.

External links

• F-term lists by a Japanese governmental agency