Daniel C. McCarthy, News Editor
Print verification systems balance accuracy against speed: If the scan rate is too high, accuracy can suffer; but competitiveness is lost if a system cannot speedily verify documents. The Vision-X print verification system from Inspectron Corp. scans credit cards, bar codes, lottery tickets and other documents traveling at speeds as high as 3000 feet per minute. At these rates, the system owes much of its accuracy to progressive-scan camera technology from Sony Electronics Inc.
Inspectron's print verification systems scan documents traveling at 3000 feet per minute -- a rate that outpaces asynchronous and line-scan technology. To maintain both the speed and accuracy of its systems, Inspectron selected progressive-scan camera technology from Sony Electronics Inc. Courtesy of Inspectron Corp.
Inspectron markets its print verification systems as the fastest and most accurate of their kind, enabling offset, laser or ink-jet printers to mass-mail complex personalized documents without textual errors. The company integrated Sony's monochrome XC-55 and XC-55BB progressive-scan cameras in the third and newest generation of its print verification system, according to Mohanan Unni, manager of electrical engineering for Inspectron. Earlier generations relied on various asynchronous reset cameras, including a Sony model, but, at the rates Inspectron's systems scanned, Unni explained, asynchronous cameras couldn't deliver the desired resolution or image quality.
"If [our system] scans two numbers that appear bunched up or against each other ... if there's any noise or smearing between them, our read is no good, in which case the system will reject the document," said Unni.
The inaccurate appearance of these two numbers, then, cannot be a function of inadequate camera speed. Inspectron evaluated several competitive progressive-scan models and found Sony's cameras provided a clearer image at rates nearly two times faster. "Sony gives nice clean images at 1200 feet per minute as compared to other progressive-scan cameras [evaluated], which were slower by at least 25 percent," said Unni.
Sony's XC-55 and XC-55BB cameras capture high-resolution images at 30 frames per second, but they can be adjusted for much higher rates. Also, asynchronous cameras and line-scan technology require brighter illumination, adding to the overall system's cost and energy use. "Sony's progressive-scan cameras were three to four times better in sensitivity than the line-scan or the async-scan CCDs," said Unni. "That means less power and longer life for the bulb."