Discrete packs on a conveyor
Cartons, pouches and bottles with gaps between them usually suit area-scan cameras. Each pack gets one triggered picture.
Guides
Line-scan or area-scan for cans, bottles and printed web?
Most inspection stations use area-scan cameras. Line-scan earns its place on continuous material, round containers and very fine detail at speed.
How do they work?
An area-scan camera takes a full picture in one exposure, like a phone camera. A line-scan camera captures one row of pixels at a time, very quickly, and builds the picture as the product moves past. The motion of the product becomes the second dimension of the image.
Which one fits the job?
Continuous web or film
Labels on a roll, printed film and sheet material have no gaps. Line-scan sees the whole width without stitching frames together.
Round containers
Spinning a can or bottle past a line-scan camera unwraps its whole surface into one flat image, with no curve and no glare from the edges.
Very fine detail across a wide view
A single line-scan camera can cover a wide web at fine pixel size where several area cameras would be needed.
Lighting needs
Line-scan needs a bright, even line of light, usually much brighter than area-scan, because each row gets a very short exposure.
Speed tracking
The line rate must follow the product speed, usually from an encoder. Without it, images stretch or squash when the line speeds up or slows down.
If the product is discrete and moves at a steady speed, start with area-scan. Move to line-scan when the job needs the full surface, the full width or fine detail at speed.
FAQ
Common questions
QIs line-scan more expensive?
The camera, the light and the encoder usually cost more, and setup takes more care. It often saves cameras on wide or round jobs.
QCan line-scan inspect labels on a bottle?
Yes, when the bottle is spun in front of the camera. That gives a single flat image of the whole label.
QWhat is an encoder for?
It reports how far the product moved, so the camera captures each row at the right moment.
QCan area-scan handle high speed?
Yes, with a short exposure or a strobe to freeze motion. Speed alone does not require line-scan.