Michael E. Byczek

Patent Search Example

The USPTO replaced it's own patent classification system in 2015 based on a new partnership with the European Patent Office (EPO) to comply with the International Patent Classification System (IPC) used by the World Intellectual Property Organization, a specialized agency of the United Nations. The EPO had been using it's own European Classification (ECLA).

The result is a standardized classification scheme called the Cooperative Patent Classification (CPC). All patent searches use the CPC.

There are an estimated 250,000 entries in the CPC. The CPC is similar to a dictionary. Each entry in the CPC is like an entry in a dictionary.

Patents are classified according to a specialized technical index. The search analyzes keywords similar to a thesaurus to locate other ways that a technical concept could be described.

The CPC is categorized as follows:

These categories are broken down into classes, subclasses, and definitions.


Within the Physics category (G) there is an entry for electrical digital data processing referred to as 06F that corresponds to G06F. Within that classification there are subclasses that correspond to software engineering (8/00), information retrieval (17/30), and security for unauthorized access to data (21/00).

Another class within Physics (G) is 06Q that corresponds to data processing methods with subclasses for e-commerce (30/00) and insurance methods (40/08).

The Electricity (H) category include basic electric elements (01) that include the subclass semiconductor devices (H01L). Another classification is H02M for conversion between AC and DC that falls under the higher class titled generation and conversion of electric power (H02).

Other classifications that fall under Electricity are transmission of digital information (H04L) and wireless communication networks (H04W).

Electric vehicles are an example where an invention could fall under multiple classification categories. One is Performing Operations and Transporting (B) under B60L (electric vehicles) and in the New Technology category (Y) under the subsection Y02T (climate change mitigation technology), such as 10/70 (energy storage for electro-mobility).

Tools to Perform a Search

The USPTO has two online databases. One for granted patents called the PatFT (Patents Full-Text and Image) and one for pending applications called AppFT (Applications Full-Text and image).

The EPO database is called Espacenet.

The WIPO database for international applications is called PATENTSCOPE.

There are also country specific databases, such as for Japan, Korea, and China.


1. A patent search begins by brainstorming words and technical terms that describe the invention, just like you would do to locate words in a dictionary, encyclopedia, or thesaurus.

2. These initial terms are matched to an entry in the CPC.

3. Each CPC entry has a designation, such as Y02T 10/70 for climate change mitigation technology for energy storage of electro-mobility.

4. Patents that have been granted or pending are organized into CPC designations. Each CPC entry (such as Y02T 10/70) will reveal every patent that has formally been entered into that classification category.

5. Analyze and compare the most relevant patents for each classification category to determine whether or not your invention can be patented.

6. Perform a search of non-patent literature, such as newspapers, websites, magazines, educational documents (i.e. dissertations), conference proceedings, books, technical catalogs, and journals to determine whether the idea was published but may not have been patented.

7. Perform a foreign search of patents using the same strategy as the USPTO.

8. The search should be well-documented, such as what databases were used, date and time of the search, which classifications were used, and which patents were analyzed.

Full Examples:

Below are two patents granted to Apple and Facebook that show that ideas are classified under numerous categories, sections, and subsections for purposes of a patent search.

The examples show how technical each CPC entry is and how each concept becomes more precise with each sub-section. Some sub-sections have been omitted to avoid repetition.

Apple Computer received a patent for interactive image thumbnails (i.e. photograph album) on October 24, 2017 (9,798,744). This patent was formally listed under the Physics (G) and Electricity (H) classification CPC categories.

Facebook received a patent for authorization and authentication based on an individual's social network (i.e. unwanted messages or non-relevant search results) on October 24, 2017 (9,798,777) with the following CPC classifications for Physics (G) and Electricity (H).

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