The main lighting the way of Video Measuring System

Lighting, is one of the key aspects of the measurement process of image measuring instrument. Good lighting scheme for the accurate measurement of a play a decisive role of various value of measured object.

In image measuring instrument, most of the following three ways: lighting surface lighting, contour lighting and coaxial illumination. Surface and contour lighting is more common, and plays a crucial role in measuring coaxial illumination for some special workpiece. Image measuring instrument in addition to surface light and light outline, and coaxial illumination, can be specially used for measurement of the work of Kong Shen and blind hole depth, and the measurement of reflection and specular workpiece, a very unique role, have a strong effect on accuracy of grasping primitives.

Surface illumination: surface light generally use the annular or punctate illumination, and the camera is in the same side. The annular lamp is a surface illumination methods commonly used, easy to install on the lens, can give a diffuse surface to provide adequate lighting. Surface illumination using a surface light source. The surface light source for general lighting application of workpiece surface, the trend is the surface light source using circular surface lighting a plurality of direction and angle of incidence. Image measuring instrument days-the company provides surface light 6 ring 8 area lighting, a total of 48 separate partitions controllable, each partition can be independently controlled switch and brightness, brightness level up to level 200. And the incident angle of each ring is different for different workpiece, ensure that can provide different illumination mode.

Contour lighting: contour lighting light source is placed at the back of the object. Different lighting and other lighting the way, because the image analysis is not reflected light, but the incident light. Contour illumination produced a strong contrast. Lighting technology application profile, surface feature will be lost, but can get contour information of objects clearly. As the source contour lighting is called contour light. Profile light let photic and non-photic parts separated, transparent place is white, lightproof place is black, so get a black and white contrast image. Outline of a point light is very important is the need to ensure that the light emitted as parallel light, to ensure that the different light intensity does not cause changes in the contour of workpiece, thereby affecting the accuracy of measurement.

Coaxial illumination: coaxial illumination is the surface with the same camera axial direction light irradiates the object. Coaxial illumination using a special half reflecting mirror, the light is reflected to the camera lens axis direction. Half mirror just reflected from the surface of the object and perpendicular to the lens light through. This kind of lighting technology coaxial source provides very useful for the realization of a flat object features and mirror surface uniform illumination. In addition, this technology can also make the surface angle changes of bright, because the surface reflection light not perpendicular to the camera lens into the lens, thereby causing the dark surface.