Optical splitter eliminates need for dual cameras
In many machine-vision applications, more than one view of an object must be obtained before an inspection pass/fail decision can be made. Often, in bottling plants, for example, both the front and back bottle labels must be inspected at the same time. Likewise, other applications call for viewing different objects that are positioned far apart. Such tasks are usually achieved by adding multiple cameras and related parts to the vision system, resulting in increased costs.
Where low-cost cameras and lenses can be used, multiple-camera units are an effective way to tackle this problem. However, if more expensive progressive-scan or large format 1k ¥ 1k cameras are needed, systems integrators are confronted by high costs.
To overcome this problem, Light Works (Toledo, OH) is offering a different multi-input device called the adjustable field splitter (AFS). "Optically splitting a single camera`s view so that it can perform many of the same functions as those of two cameras is a way to reduce costs in high-per formance machine-vision systems," says Spencer Luster, founder of Light Works. "Space and set-up time can likewise be reduced," he adds.
A typical configuration, priced from $1470 to $2200, consists of an AFS that is lens- or camera-mountable and achieves view splitting with an on-axis prism configured for external reflections. "The AFS produces adjacent images on the same detector," says Luster. The splitter includes fold mirrors, extension tubes, and rotary joints that create articulated periscope arms, thereby increasing the AFS flexibility.
In use, the AFS allows the viewing of two widely separated objects or fields or the same object from two different angles, including opposite sides. "In many cases, the AFS provides the developer with the same results as those from a two-camera system, but for significantly less cost," contends Luster.
