Memos from the last millennium

Lightness, quickness, exactitude, visibility, and multiplicity were the qualities that the Italian writer Italo Calvino saw as the essential values for 21st century literature. His book,Six Memos for the Next Millennium, was based on a series of lectures that were to be presented as part of the Charles Eliot Norton Lectures at Harvard University in 1985. Unfortunately, the author died before the lectures were to be presented, finishing all but the last lecture. The sixth but unfinished lecture was to be about consistency.

As a renowned author of fiction and fantastic tales, Calvino could be expected to take some imaginative leaps, yet he could not have made the leap into this century where fast semiconductor and web-inspection systems, infrared imaging, high-brightness LED lighting, and solid-state cameras are commonplace. Infrared imaging, for example, is now being used increasingly in machine-vision systems and is the topic of two articles this month, one on dual-band IR QWIP cameras and one describing the many IR detectors now available. In another article, contributing editor Winn Hardin reveals how, with efficiencies and power improving, high-brightness LEDs are being used in traditional applications in the machine-vision market and also bringing light to novel applications.

Despite the numerous lighting, software, and hardware products that are available to the system integrator, it is perhaps the consistency of operation that proves most important to machine-vision developers. While such off-the-shelf products must be fast, lightweight, and often multifunctional, they must be integrated into systems that provide repeatable results to the manufacturing industry.

TRUE QUALITIES

This month’s Product Focus article also reflects many of Calvino’s values-especially that of consistency-by discussing the sometimes controversial topic of CMOS camera-performance specifications and true system performance. The controversy includes sometimes abused specifications such as maximum signal-to-noise ratio, absolute sensitivity, and dynamic range. Indeed, Wilson’s article points out the difficulties to be found when trying to compare one camera’s performance to another, describes some techniques that may be helpful to camera users when trying to understand actual performance, and urges more steps such as the one underway in the EMVA 1288 camera-specification standard initiative to maintain consistency.

One obvious benefit in maintaining consistent inspection is to be found in the semiconductor industry. As editor Andy Wilson writes, a combination of products such as LED lighting, multiple cameras, and custom hardware can be integrated into a very effective system for checking the bumps on wafers. In our Business Views interview, system-integrator Mark Shelton describes how web-inspection techniques now enable lace and other valuable textiles to be checked very quickly. By ensuring consistent results during manufacturing processes, machine vision maintains the quality and integrity of these products.

W. Conard Holton
Editor in Chief
[email protected]