You can search documents using the following classification codes: IPC, ECLA, ICO, main US, main and additional US, CPC, and Locarno (Designs).
You can add up to one classification box. To connect the two classifications, you can choose between the AND and the OR operators.
Wildcards and Operators
The only wildcard to be used when searching for incomplete codes is the unlimited wildcard +.
A comma is equivalent to an OR, while a space is equivalent to an AND.
Only Boolean operators are to be used.
International classification (IPC)
The International Patent Classification codes are assigned by most national or regional patent offices.
There are approximately 70,000 IPC codes.
Subclass: A63F
Group: E21B-003
Subgroup: E21B-003/02
Subdivision: C21D-001/773
These codes can be searched at the subclass, group, subgroup or sub-division levels.
European classification (ECLA) and In computer only classification (ICO)
The European Patent Office assigns these classification codes to patents published in many countries worldwide, to organize their own search files. The ECLA codes are revised monthly, with the new codes being applied retroactively.
There are about 140 000 ECLA codes.
Subclass: A63F
Group: E21B-003
Subgroup: E21B-003/02
Subdivision: C12Q-001/68D2E1
These codes can be searched at the subclass, group, subgroup or sub-division levels.
Additional notes from the originating IPC class are shown in square brackets and preceded by the letter N.
Derived from the ECLA classification, In Computer Only classification is used by the European Patent Office to describe minor features of the invention or the characteristics for which there is no ECLA code.
There are about 200,000 ICO codes.
The ICO code structure is identical to that of the ECLA codes except the first letter that differs: K, L, M, N, P, R, S and T. It is used to classify the additional information.
ICO orthogonal codes are used to classify inventions according to different criteria than ECLA codes.
Subclass: S21Y
Group: S21Y-002
Subgroup: S21Y-002/20
Subdivision: S21Y-002/205
These codes can be searched at the subclass, group, subgroup or sub-division levels.
US main and US main and cross reference classifications (PCL)
The US Patent Office assigns these classification codes to US patent publications to organize their own search files.
In the drop-down menu, you can choose only the main code or both types of code. US classification codes are revised every two months and retroactively applied.
Main class: 108
Subclass: 108051
Decimal: 108051110
Extension: 188250000B
These codes can be searched at the main class (3 digits) subclass (6 digits), the full decimal code (9 digits) or the complete code with extension (9 digits plus 1 to 3 alphabetic characters) levels.
Cooperative patent classification (CPC)
The CPC codes have been developed jointly by the European Patent Office (EPO) and the US Patent Office (USPTO).
From January 1, 2013, the EPO examiners attribute CPC classification codes to new patents. Patent classified with ECLA/ICO codes have been reclassified with the CPC codes based on a conversion table established by the EPO.
Until the December 31, 2014, the USPTO can classify with CPC and PCL codes, only with the PCL codes, either CPC and PCL codes.
There are about 250,000 CPC codes.
Conversion rules:
Their format is based on the IPC codes
The letters of the subdivisions of the ECLA codes are replaced by numbers. There may be up to 6 digits after the / separator
The ICO mirrors are incorporated into the CPC codes
The Y section of the ICO codes is fully established.
For ICO orthogonal codes, a 2 is added after the subclass to create a CPC 2000 series (example: A61H-2230/04)
Schematic of a CPC code:
Position 1: section (A to H and Y) =>H
Positions 2 and 3: class =>H01
Position 4: subclass => H01L
Positions 5 to 8: main group =>H01L-021
Position 9: separator =>H01L-021.
Positions 10 to 15: subgroup =>H01L-021/28264
These codes can be searched at the section, class etc. levels.
The notes in brackets are the ECLA classifications that have been preserved in the CPC classification.
Locarno classification
Locarno classification is reserved for Designs.
It is made up of 32 classes (1 to 32) and of subclasses.
Class: 12