Optical Comparator

Compare OPTICAL COMPARATORS. An optical comparator comes as the bench (small screen) optical comparator and floor (large screen) optical comparator. The small screen comparators have a max screen of 16 inches diameter. The large screen comparators have larger screens, up to 60 inches in diameter.

Optical comparators perform edge detection using precision optics. Optical lenses have been available for many years. In an optical comparator, the item to be inspected is placed in a path of light in such a manner that it passes by an edge of the object. The light path may be horizontal or vertical. Horizontal light paths are to inspect small, light weight objects. Vertical light paths are for larger, heavier, objects.

The light is captured by a lens which passes the light beam along magnifying the image and displaying it on a glass screen. When an image is viewed through a magnifying lens, the result is an inverted, turned around, image. This is what is observed in the basic optical comparator. With the use of additional lenses in the path of the light, these problems can be corected. The most common correction is to turn the image arounhd. The result being an upside down image, but with correct side to side view. This makes the interpretation of the image being inspected easier. Most comparators come with the corrected upside down image. Completely corrected images are availble and are offered more frequently as the manufacturing cost of optics is lowered. This is particularly true with the larger optical comparators where the incremental cost for the more complex optics are more easily absorbed.