Linear cameras mount a linear array sensor (1D) instead of a matrix sensor (area, 2D type). This sensor contains only one row of pixels or two typically. Although sensors with several rows are possible, the count will be very small (4, 6, 12). The number of columns is always much higher, so that the result is a sensor with a linear aspect.
These linear cameras compose the image by joining multiple linear snapshots captures.
Typical resolutions, or rather, typical pixel matrix formats are: 1024 x 1; 2048x1; 2048x2; 4096x2; 8192x1/4/6/12; 16384x1
So the sensor has 1, 2, 4, 6, 12 rows and 1024 2048, 4096, 8192, 16384 columns. Due to the number of columns, these cameras are known as 1K, 2K, 4K, 8K, or 16K pixel resolution cameras.
It must be taken into account that a sensor with many columns will have a large format and this will require the use of suitable lenses. From 2048 px the lens must be threaded F or larger, not serving those with C-mount. The use of lenses smaller than the appropriate format will cause vignetting.
As for area scan cameras, versions with a color or monochrome (black and white) sensor can be chosen.
The low number of rows allows a very high image acquisition speed. Rates of thousands of images per second (fps: frames per second) or ranges of the KHz order are reached in the capture of images.
The typical applications of linear cameras reside in the inspection of continuous media (continuous inspection, "web inspection"): casting, paper, textiles, plastics, metal coils, conveyor belts, inspection of cylindrical or round parts, etc…These are cases in which images must be captured at high speed and either the object to be inspected or the camera is in motion, so that one moves with respect to the other. For this reason, they are called line scan cameras. The complete image of the object is later reconstructed line by line, or it is enough with the programming of alarms for defect detection or for classification applications.
The synchronization between the capture speed of the camera and that of the medium to be measured is of great relevance.
Some industries and applications that benefit from this type of camera, line scan, are:
- solar (photovoltaic panels)
- general industry: high speed object sorting
At Iberoptics we can offer you line scan cameras both in the visible and in the infrared SWIR zone (900-1700 nm). The former mount CMOS sensors while the latter implement InGaAs sensors.
- HIK-CL: family of linear cameras in the visible, with GigE or CameraLink interface and resolution up to 16384 x 1 px
- NIT- LiSa-SWIR: Infrared line camera, CameraLink, 2048 x 1 px, 60 KHz
We are the distributors of HIK Robotics and NIT (New Imaging Technologies) in Portugal and Spain.
Other machine (artificial) vision products that might be of your interest:
Area scan cameras Line scan cameras Smart cameras
Zoom / autofocus cameras Polarized cameras 3D cameras
Board cameras Polyspectral cameras SWIR cameras
Line and pattern lasers LED lighting Industrial PCs
Code readers Filters Lenses (fixed f., zoom, telecentric)