Vision industry standardizes on Camera Link
Until recently, digital-camera and frame-grabber vendors supplied a variety of custom connectors and cables. These components proved bulky, expensive, cumbersome, and dissimilar.
Until recently, digital-camera and frame-grabber vendors supplied a variety of custom connectors and cables. These components proved bulky, expensive, cumbersome, and dissimilar. To effectively develop machine-vision systems, systems integrators needed to specify specific cameras and frame grabbers with special cables and connectors to meet design goals.
To overcome this compatibility problem and to promote plug-and-play connectivity, a consortium of more than a dozen camera and frame-grabber companies met last year and proposed a Camera Link digital serial interface standard to make camera-to-frame-grabber-to-PC connections easier and cheaper. The Camera Link standard is based on the low-voltage differential-signaling Channel Link technology and chipsets from National Semiconductor (Santa Clara, CA). Whereas the Camera Link standard does alleviate the problems of camera-to-computer connectivity, it is still not a plug-and-play interface, reports editor Andy Wilson in this issue's Product Focus (see p. 34). Although many camera vendors are using Camera Link to reduce the cabling needed, their linescan, time-delay integration, and area-array cameras are far from standard. Despite this, many camera and frame-grabber vendors have endorsed the Camera Link standard.
No matter what connectivity standards are used, cameras and frame grabbers continue to save costs and improve yields in a variety of industrial applications. For example, automotive-manufacturer Volkswagen pays close attention to the mechanical quality of each gear prior to assembly into finished gearboxes. Enlisting the help of a systems integrator, it developed a vision system that inspects each gear, tooth-by-tooth, from both sides using as many as four cameras, as described by Andy Wilson (see p. 9).
In another industrial process, a microsphere (solder-ball) producer wanted to improve its production yield using vision and imaging technology. The producer installed a machine-vision system that monitors droplet size and quality and automatically extracts diameter information about the microspheres. According to contributing editor Charles Masi, the vision system collects data on more than ten times the number of spheres than the previous system could in a typical production run (see p. 28).
In another industrial application, a manufacturer of machined-metal air diffusers that enable inflation of automobile airbags changed from manual inspection of the diffusers to a custom-developed vision-based system. The dual-camera-based system accurately measures several dimensions of the diffusers derived from five exposures taken and processed in about 1 s. This system, says contributing editor Larry Curran, eliminated as many as nine inspectors, saved money, and markedly boosted production (see p. 22).
George Kotelly,Editor in Chief