Over two years ago, the Intellogist Blog discussed
Chinese patent searching on a budget. The free search options for Chinese patent documents included in that post were
SIPO,
CNIPR/C-Pat,
CNPAT,
Surf IP and
IPEXL. We later published a post on the free Chinese patent search options on
Zhihuiya.com.
Over the past two years, these websites have all undergone many
changes, and some of the search systems are no longer freely available.
Surf IP and C-Pat are no longer available online, and Zhihuiya.com is
now redirected to CN.Patsnap.com, which only appears to be available for
subscribed users. Continue reading to learn about the free Chinese
patent search options currently available through the remaining search
systems: SIPO, CNIPR, CNPAT, and IPEXL (which draws on SIPO data). If
you need a global prior art search conducted by a professional searcher
fluent in Chinese, you can always
contact patent search professionals who have access to both free and subscription patent databases with broad Chinese patent coverage.
After the jump, learn about the free
Chinese patent search options available through SIPO, CNIPR, CNPAT, and IPEXL!
SIPO
The
State Intellectual Property Office (SIPO) of the PRC (People’s Republic of China) offers a free English patent search interface for invention and utility models.
The search will be conducted on English-language titles and abstracts
in the collection. Users can also produce a full text machine
translation of individual documents. The machine translation technology,
called the China Patent Machine Translation system (CPMT), was
researched and developed by China Patent Information Center.
Users can access the patent search system through the
SIPO English-language homepage
by selecting the “Patent Search” link in the menu bar on the right side
of the page. Users can select to search within the Invention or Utility
Model databases (or within both). Users enter queries within multiple
fields by utilizing the top half of the site to search by Publication
Number, Publication Date, Application Number, Application Date, Title,
Abstract,
IPC,
Applicant, Inventor, Patent Agent, Patent Agency Code, Priority, and
Province/Country Code. Users can also enter queries in the Combination
Search at the bottom of the page, where they can search within multiple
fields, use parentheses, and join search terms by Boolean operators. A
guide for correctly formatting search terms and allowable operators is
found under “
Help.”
Users can choose to sort their results by any field listed in the
“Sort By” drop-down menu at the top of the search page, in ascending or
descending order.
When users select a result from the record list to view, they will
first be taken to a bibliographic record of the patent document. Users
can view a machine translation of the full document by selecting
“Machine Translation” at the bottom of the page. Upon first selecting
the “Machine Translation” button for a particular record, an
English-language translation of the claims will be displayed. To see the
rest of the specification, users should scroll to the bottom of the
page and select the “Description” button.
The EPO website provides guidance on how to utilize other free search tools provided by SIPO:

The English-language bibliographic data for a Chinese patent record on the SIPO website.
CNIPR
China Intellectual Property Net (CNIPR) is a platform for Chinese
patent searching, monitoring, document translation, document delivery,
and Chinese Pharmaceutical patent searches, maintained by the
Intellectual Property Publishing House (IPPH). The free Chinese patent
search platform C-Pat is no longer available through CNIPR, but users
can subscribe to an English-language version of CNIPR.
See
this page on the English version of the CNIPR website for pricing information.
Users can still search for Chinese patent documents on the
Chinese-language version of the CNIPR website for free. The EPO provides a step-by-step guide on
retrieving Chinese documents from IPPH/SIPO’s CNIPR database.
A fielded search form (in Chinese) allows users to search for Chinese
patents, utility models, designs, granted patents, TW patents, and HK
patents (as of September 2012, additional authority coverage appears to
be available). The full record displays bibliographic data, abstract,
main claim, legal status, citations, patent family, and automated
abstract/keywords. The EPO guide indicates that users can download the
document in TIFF format, when available.

A Chinese-language record on CNIPR.
CNPAT
China Patent Database (CNPAT) is a free online search platform for
Chinese patents, patent applications, utility models, and designs,
created by the China Patent Information Center. A majority of the
interface only is available in Chinese, although users can view the
fields for the advanced and expert search forms in English. The site
includes a quick keyword search form (Chinese only), a fielded search
form (field labels available in English), and a
command line interface
(field labels available in English). Users can choose to included
thumbnail images in the search results (which are only viewable in
Chinese). The full record may include bibliographic data (including the
first claim, when available), drawings, the full-text PDF, full claims,
and legal status. It appears that a translation service is available for
title, abstract, and first claim for “VIP Users Only.”

A Chinese-language record on CNPAT.
IPEXL
Users can
create a free account
to log in to IPEXL (maintained by the Intellectual Property Exchange)
and search through the following collections for free: US, US
applications, China (native), and Singapore. The CN patent collection
includes Chinese-language patent data only, available through SIPO. A
fielded form allows users to search through a variety of fields
(abstract, title, inventor, attorney, agency, applicant/assignee, IPC,
etc.), and users can also limit the search by document number,
publication data, application date, and patent type. The list of search
results and full document records include basic bibliographic
information in Chinese (title, inventor, applicant, attorney, abstract,
IPC, document number, publication date. application date, etc.). Users
can view the original source of the data on the SIPO website, create a
permanent link to share the record, or create a graph of citation
relationships for the record.

A Chinese-language record on IPEXL.
Conclusion
All Chinese patent search data originates from SIPO, although each
website’s search interface provides a different user experience. While
English translation options on CNIPR and CNPAT are only available for
subscribed users, both SIPO and IPEXL offer a free English search
interface (although users on IPEXL must use Chinese-language queries).
English-language users will probably have the easiest time utilizing the
SIPO English-language search interface, since the user can enter
queries in English and create full English-language machine translations
for patent records. The SIPO website also provides additional free
services (in Chinese), such as legal status search and file history
information.
Although English-language patent searchers may be able to conduct a
basic initial search of a portion of SIPO’s Chinese patent collection
using the machine translation services on the SIPO website, there is no
substitute for a native-language searcher when conducting a
comprehensive prior art search. Always contact a
patent search professional
who is fluent in Chinese and has access to global patent and non-patent
literature search systems if you need a patent search for business or
legal purposes.
Do you know of other free Chinese patent search options?