Patent drawing

[4] Under the Patent Cooperation Treaty, Article 7 PCT notably provides that the drawings are required when they are necessary for the understanding of the invention.

[5] Rule 11.13 PCT specifies special physical requirements for drawings in an international application.

[8] The drawing must show every feature of the invention specified in the claims, and is required by the U.S. patent office rules to be in a particular form.

The following rule, reproduced from title 37 of the Code of Federal Regulations, relates to the standards for drawings:[8] [clarification needed] From 1790 to 1880 in the US, patent models were required.

In some cases, an inventor may still want to present a "working model" as an evidence to prove actual reduction to practice in an interference proceeding.

By then, the rate of patent grants had grown to about 20 per year and the time burden on the Secretary of State was considered to be too burdensome.

[8] Black and white photographs are not ordinarily permitted in utility and design patent applications, unless this is the only practicable medium for illustrating the claimed invention.

For example, photographs of electrophoresis gels, blots, autoradiographs, cell cultures, histological tissue cross sections, animals, plants, in vivo imaging, etc.