There are two main camera types used for machine vision applications: Area scan cameras and line scan cameras. Generally the use of an area scan camera is technically less demanding than a line scan camera, therefore area scan cameras are the preferred solution for general machine vision systems, while line scan can create solutions not easily achieved using area scan. In the following sections both types of cameras are discussed along with examples of application areas, highlighting the need for both, and the fact that in some applications either can be appropriate.
The basic sensor technologies are common to both types. The term "area" refers to the type of sensor inside the camera - one that occupies an area rather than a single line, as is the case with line scan cameras. The image produced by an area scan sensor is two dimensional, historically with an aspect ratio of 4:3. The ratio has been inherited from broadcast specifications, although there are many area scan cameras with square or rectangular sensors that do not conform to this 'standard video'. The rapid development of high definition TV is also increasing the demand for wide format cameras with different aspect ratios such as 16:9.