A line-scan camera is a system for producing two-dimensional images using a single sensor element. They normally consist of a rapidly rotating mirror or prism placed in front of the sensor to provide scanning in one direction while the movement of the recording material, often

photographic film Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of th ...

, provides scanning in the second direction. They are similar in concept to the

drum scanner An image scanner—often abbreviated to just scanner—is a device that optically scans images, printed text, handwriting or an object and converts it to a digital image. Commonly used in offices are variations of the desktop ''flatbed scanner'' w ...

, differing largely in form and function. Line scanning was widely used for both visible light and, more commonly,

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

imagery from the 1960s through the 1980s, especially in

aerial reconnaissance Aerial reconnaissance is reconnaissance for a military or strategic purpose that is conducted using reconnaissance aircraft. The role of reconnaissance can fulfil a variety of requirements including artillery spotting, the collection of ima ...

. 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. Another famous example is the camera on

Pioneer 10 ''Pioneer 10'' (originally designated Pioneer F) is an American space probe, launched in 1972 and weighing , that completed the first mission to the planet Jupiter. Thereafter, ''Pioneer 10'' became the first of five artificial objects to ach ...

, which used a fixed-position

polarimeter A polarimeter is a scientific instrument used to measure the angle of rotation caused by passing polarized light through an optically active substance.rotating line camera A rotating line camera is a digital camera that uses a linear CCD array to assemble a digital image as the camera rotates. The CCD array may consist of three sensor lines, one for each RGB color channel. Advanced rotating line cameras may have mul ...

s. They are also used as the timing systems for races where a "photo finish" may occur. Today the term line scanner is more commonly used to describe desktop flatbed

image scanner An image scanner—often abbreviated to just scanner—is a device that optically scans images, printed text, handwriting or an object and converts it to a digital image. Commonly used in offices are variations of the desktop ''flatbed scanner'' ...

s, although these consist of a one-dimensional stripe of sensors instead of a single sensor. Modern line-scan cameras may be built in a similar fashion, using a stripe of sensors to image in one dimension and the movement of the camera or object in the other.

References

* * * {{Photo-stub Cameras by type