Line-scan camera

A line-scan camera is a system for producing two-dimensional images using a single sensor element.

Line scanning was widely used for both visible light and, more commonly, infrared imagery from the 1960s through the 1980s, especially in aerial reconnaissance.

Typical systems include the one used on the Corona spy satellites, which used a telescope that moved side-to-side while film was pulled across it, producing a series of stripes.

The introduction of sensitive array sensors in the 1980s and especially 1990s had led to the gradual disappearance of the technique in many roles.

One common use is in manufacturing to inspect printed surfaces like labels on products, in which case they are referred to as rotating line cameras.

Pioneer 10 's famous images of Jupiter were produced through the line-scan process, with the spacecraft's rotation scanning in one direction and movement in space in the other. Though normally not visible, this particular image retains artifacts of the scanning process.
Modern line-scan camera image of a San Francisco cable car, imaged at 4000 frames per second. Note the background, which was unmoving and thus appears as a single vertical stripe.
Line scanning used in strip photography to capture the photo finish of a foot race