International Patent Classification
Search Tips - February 2000
What are International Patent Classifications (IPC)?
IPCs are a comprehensive subject classification system applied to all patents
by the patent-issuing authorities.
You can find a full listing of the 7th revision of the International Patent Classifications at http://classifications.wipo.int/fulltext/new_ipc (you will also find details here of the main changes to the previous (6th) version of IPC codes).
How can IPC codes assist my searching?
Derwent includes the IPC codes as part of the Derwent World Patents
Index (Derwent WPI) record. This means that you can use IPCs to enhance
your subject searches on Derwent WPI, helping you retrieve records where
the invention is described in ways that you might not have thought and included
in a word search. A frequency analysis of IPCs, using RANK, MEMSORT or ANALYSE,
can be a very useful way of investigating the activities of a competitor company.
Even if various patent-issuing authorities apply different IPCs to the same invention, they will all be present in the Derwent WPI record, maximising the effectiveness of your searching
How do I incorporate IPCs into my Derwent WPI search?
The codes are extremely useful for when you are searching for specific technologies
and can be used for varying levels of detail.
An example of the hierarchy of IPC codes taken from the WIPO website:
| SECTION H | ELECTRICITY |
| H 04 | ELECTRIC COMMUNICATION TECHNIQUE |
| H 04 B | TRANSMISSION |
| 7/00 | Radio transmission systems, i.e. using radiation field |
| 7/208 | Frequency-division multiple access |
How do I know which level of classification to search?
(Using the above IPC code examples)
If you were looking specifically for records relating to Electric transmission
systems for frequency-division multiple access, you should search the complete
IPC Code: h04b-007-208
If your search was less specific and you were looking for records relating to Electric radio transmission systems you should search the 'main group' level of the IPC Code: h04b-007
If your search is more general again and you were searching for records relating to any type of electric communication technique transmission, you should search the 'subclass' level of the IPC Code: h04b
If you just require a general search to identify all records relating to Electric Communication Technique then you can search the class level of the IPC code: H04
Search commands for searching IPC codes
| Dialog | Questel.Orbit | STN (Derwent format)* | |
| Search IPC Subgroup level | s ic=h04b-007/208 | /IC h04b-007/208 | s h04b-007-208/ic |
| Search IPC Main group level | s ic=h04b-007 | /ic h04b-007 | s h04b-007/ic |
| Search IPC Subclass level | s ic=h04b | /ic h04b | s h04b/ic |
| Search IPC Class level | s ic=h04? ? | /ic h04# | s h04!/ic |
*Alternatively you can also search IPCs on STN using the STN format e.g. h04b007-208
How do I search a range of IPC Codes?
You can also search a range of IPC Codes if the subject that you are interested
in covers a number of codes.
| SECTION H | ELECTRICITY |
| H 04 | ELECTRIC COMMUNICATION TECHNIQUE |
| H 04 B | TRANSMISSION |
| 7/00 | Radio transmission systems, i.e. using radiation field |
| 7/185 | ...Space-based or airborne stations |
| 7/19 | ....Earth-synchronous stations |
| 7/195 | ....Non-synchronous stations |
| 7/204 | ...Multiple access |
| 7/208 | ....Frequency-division multiple access |
| 7/212 | ....Time-division multiple access |
| 7/216 | ....Code-division or speed-spectrum multiple access |
(Using the above IPC code examples)
To search for Radio transmission relay systems that have space-based or airborne stations and multiple access (IPC codes h04-007/185 to h04b-007/216) type the following commands:
| Dialog | Questel.Orbit | STN (Derwent format) |
| s IC=h04b-007/185:h04b-007/216 | /IC ho4b-007/185:h04b-007/216 | s h04b-007/ipc(t)18500-21600/sgr |
How do I find out more about IPCs?
Dialog, Questel.Orbit and STN all offer a number of features within their search
language to enable more advanced searching of IPC Codes. Please contact the
relevant help desk for further information.
If you require any further assistance searching Derwent files please contact our Help Desk at custserv@derwent.co.uk
Derwent run a range of public training classes throughout Europe and the US to enable you to learn more about getting the most out of searching Derwent files online. Classes are normally run free of charge. Please see our current training schedule.
Further Information
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