Machine Vision Guide - Introduction and Overview

Introduction and Overview

Introduction

Today, more and more manufacturers are using machine vision technology to improve their productivity and reduce costs. Machine vision integrates optical components with computerized control systems to achieve greater productivity from existing automated manufacturing equipment. The key factors driving this trend are the sharp reduction in computer hardware cost and the dramatically increased power of personal computers. Many vision systems are running on Pentium� class processors, with no special hardware. As the field grows, more powerful vision software is becoming available.

At the core of this growth in machine vision are manufacturers� ever-increasing demands for finer control over the quality of manufactured parts. Whether it is the medical industry�s desire to reduce liability, or the consumer market�s need to lower costs, 100 percent part inspection is becoming the norm. When a single bad part can jeopardize a customer relationship or spur a lawsuit, manufacturers seek to meet quality standards that far exceed the capabilities of older technologies.

Machine vision systems come in many forms. Some systems use an analog camera and digitize the image with a frame grabber. An increasing number of systems use digital cameras that, like any other peripheral device, send data directly to PC memory. For some applications, �smart cameras� provide complete vision systems in a single box. Despite their differences, all these systems depend on the front-end optics to provide a high quality image to the sensor.

The image is the only source of information for a machine vision system. The quality of the analysis is dependent on the quality of the image, and the quality of the image is determined by the appropriate choice of optics. Software cannot correct for poor image quality. Nonetheless, optics are the most neglected aspect of a vision system.

Lighting and lens must work together to collect the relevant information about the object. The lighting must illuminate each feature, provide good contrast, and minimize confusing artifacts. The lens must resolve features over the entire object and a range of working distances. For alignment and gauging applications, the lens must present the image in a fixed geometry, so that the image location is precisely calibrated to the object�s position in space. The lens can image only the rays launched by the lighting; the lighting must launch only rays that contribute to the desired image. The success of the machine vision system depends on the performance of the optics.

Machine vision continues to expand into new applications. Camera size and cost have decreased. High-resolution digital cameras are in common use. Smart Cameras make entire vision systems available for less than the cost of a processor alone only a few years ago. Geometrical pattern matching software has improved the precision and robustness of object location. Each new development leads to new requirements for high performance optics.

Melles Griot, a leader in optics technology for three decades, is a major resource for professionals in many fields who are working with machine vision systems. Our engineers understand the precision and accuracy required for the most critical components of vision systems � the optics. However complex your requirements, Melles Griot has the expertise and the experience to maximize the power of your machine vision system.