Google Patents is a search engine from Google that indexes patents and patent applications from the United States Patent and Trademark Office (USPTO), European Patent Office (EPO), World Intellectual Property Organization (WIPO), Deutsches Patent- und Markenamt (DPMA), Canadian Intellectual Property Office (CIPO), and China's State Intellectual Property Office (SIPO). These documents include the entire collection of granted patents and published patent applications from each database (which belong to the public domain). US patent documents date back to 1790, EPO and WIPO to 1978. Optical character recognition (OCR) has been performed on the older US patents to make them searchable, and Google Translate has been used on all foreign patents to make the English translations searchable.