Information about International Patent Classification (IPC)can be found in patstat usign table TLS209_appln_ipc
The PATSTAT database only contains IPC8 symbols; therefore PATSTAT users do not need to worry about previous IPC classification schemes IPC 1 to 7, when doing statistical analysis based on IPC codes. IPC 1 to 7 have all been reclassified to the latest IPC 8 version.
DOCDB contains the MCD Master Classification Database. The MCD has IPC symbols allocated to over 90% of the documents in DOCDB; the remaining 10% older documents are unlikely ever to be classified.
more details on wipo website:
http://www.wipo.int/classifications/ipc/en/
http://www.wipo.int/classifications/ipc/en/general/statistics.html
http://www.wipo.int/export/sites/www/classifications/ipc/en/guide/guide_ipc.pdf
TLS209 contains also a field, not well described in the documentation, named 'ipc_version' referring to the date of IPC8 version used for classifying the application.
Running a count query on 2014b data we get these numbers of applications for each ipc version:
'2006-01-01', 11815023
'2007-01-01', 10163
'2007-10-01', 8799
'2008-01-01', 12337
'2008-04-01', 1531
'2009-01-01', 141904
'2010-01-01', 101411
'2011-01-01', 110327
'2012-01-01', 80867
'2013-01-01', 89686
'2014-01-01', 6992
We can also run a check to see how many applications have multiple versions in their ipcs
they are 200K out of 3118K applications
Thus we can deduce the ipc verion indicates if the given ipc value is result of the origina IPC8 or from a further revision (that mainly introduce amendments or changes for new technologies).
A good resume as well as another interesting point can be eventually noted from this OECD paper (see page 10)
In PATSTAT, IPC codes of patent documents are converted into the latest available edition of the IPC
classification, i.e. 8th edition, entered into force in 2006. Patents based on previous editions of the IPC classification have thus been re-classified accordingly. Also, due to the emergence of new technologies, sometimes no one-to-one correspondence exists between old and new IPC editions, and older IPC codes may correspond to many IPC 8th edition codes. Hence, patents filed before the mid-2000s may feature a broader range of IPC-7 codes than later patents: five codes on average for patents filed in 2000 compared to around 2.5 codes per patent in the late 2000s. As can be seen from the figure below, each IPC code in force at the date of patenting has been allocated in PATSTAT to around two codes of the IPC 8th edition.
As a consequence, the patent scope index tends to be overestimated before the mid-2000s. For example, the patent scope index of micro- and nano-technology patents gets seemingly divided by three between 1999 and 2009.
The PATSTAT database only contains IPC8 symbols; therefore PATSTAT users do not need to worry about previous IPC classification schemes IPC 1 to 7, when doing statistical analysis based on IPC codes. IPC 1 to 7 have all been reclassified to the latest IPC 8 version.
DOCDB contains the MCD Master Classification Database. The MCD has IPC symbols allocated to over 90% of the documents in DOCDB; the remaining 10% older documents are unlikely ever to be classified.
more details on wipo website:
http://www.wipo.int/classifications/ipc/en/
http://www.wipo.int/classifications/ipc/en/general/statistics.html
http://www.wipo.int/export/sites/www/classifications/ipc/en/guide/guide_ipc.pdf
TLS209 contains also a field, not well described in the documentation, named 'ipc_version' referring to the date of IPC8 version used for classifying the application.
Running a count query on 2014b data we get these numbers of applications for each ipc version:
'2006-01-01', 11815023
'2007-01-01', 10163
'2007-10-01', 8799
'2008-01-01', 12337
'2008-04-01', 1531
'2009-01-01', 141904
'2010-01-01', 101411
'2011-01-01', 110327
'2012-01-01', 80867
'2013-01-01', 89686
'2014-01-01', 6992
We can also run a check to see how many applications have multiple versions in their ipcs
they are 200K out of 3118K applications
Thus we can deduce the ipc verion indicates if the given ipc value is result of the origina IPC8 or from a further revision (that mainly introduce amendments or changes for new technologies).
A good resume as well as another interesting point can be eventually noted from this OECD paper (see page 10)
In PATSTAT, IPC codes of patent documents are converted into the latest available edition of the IPC
classification, i.e. 8th edition, entered into force in 2006. Patents based on previous editions of the IPC classification have thus been re-classified accordingly. Also, due to the emergence of new technologies, sometimes no one-to-one correspondence exists between old and new IPC editions, and older IPC codes may correspond to many IPC 8th edition codes. Hence, patents filed before the mid-2000s may feature a broader range of IPC-7 codes than later patents: five codes on average for patents filed in 2000 compared to around 2.5 codes per patent in the late 2000s. As can be seen from the figure below, each IPC code in force at the date of patenting has been allocated in PATSTAT to around two codes of the IPC 8th edition.
As a consequence, the patent scope index tends to be overestimated before the mid-2000s. For example, the patent scope index of micro- and nano-technology patents gets seemingly divided by three between 1999 and 2009.
