Optical Inspection In Industry

Abstract

The potential for automatic optical inspection in industry is clearly great since virtually every product is inspected at least once. Although the ready availability of the basic components needed, such as light sources, scanners, image analysers and display systems, has led to the design and application of numerous systems, many quality assurance engineers still need convincing that inspectors can in fact be replaced by machines. The advantages and benefits to be derived from using automated inspection will be discussed, together with techniques which can be used to overcome some of the problems met in high speed automated systems which may be operating in hostile environments. Thresholds of acceptance need to be established in relation to the particular problem and this aspect of inspection traditionally gives rise to the greatest area of disagreement between the supplier of equipment and the customer. The need to agree on the precise method of measurement of the relevant parameter and means for system calibration will be stressed when describing three recently developed inspection systems using a scanned laser, a white light TV system and infrared radiation for the inspection of strip products, microscopic flaws on optical components, and stress patterns on structures subjected to dynamic loading.