Continuing the series of posts explaining the parts of a patent, today we move on the drawings. A drawing is required when it is necessary to understand the patent application. Most applications have drawings. Like the abstract, drawings often provide a quick way of figuring out what the invention is. Drawings must show every part of the invention that is claimed in the patent. Drawings are labeled with part numbers so you can read the patent application and check the drawing for the part referred to in the description.
Drawings are generally black and white line drawings – in rare occasions color is permitted. Likewise, photographs are usually not allowed. The drawings are meant to clearly show the parts and features of the invention, and the use color or photographs can make depiction of the parts difficult.