Glossary

AOI
Automated Optical Inspection

Back lighting
Placement of a light source behind an object to highlight its shape, useful to hide surface details and emphasize the outline of an object.

BGA
Ball-Grid Array - a type of surface-mount packaging used for integrated circuits.

CTF
Contrast Transfer Function.

Flange distance
Distance from the mounting flange (the "metal ring" in rear part of the lens) to the camera detector plane.

F-Number, F#
The ratio of the lens focal length to the diameter of the entrance pupil.

FOV or Field of view
The area that is visible by a machine vision system. Depends on the type of the lens and on the working distance between object and camera.

LED
Light Emitting Diode.

Line scan camera
A camera based on a single row of photodectors.

Machine vision
Also called Artificial Vision, it is a wide-ranging term referring to the applications of computer vision to industry and manufacturing.

Metrology
The science of measurement: a key application of many machine vision technologies.

OCR
Optical Character Recognition: dedicated software to process images of written text into a computer-understandable format.

PCB
Printed Circuit Board.

Scheimpflug
Refers to the Scheimpflug principle: a geometric rule that describes the orientation of the plane of focus of an optical system (such as a camera) when the lens plane is not parallel to the image plane.

SMD
Surface-Mounted Device.

Telecentricity
Refers to the property of a telecentric lens to keep chief optical rays (rays passing through the centre of the aperture stop) parallel to the optical axis.

Working distance
Distance (usually in mm) from the optimal focus plane where the object is placed to the front end of the lens mechanics.