Testing requirements

Detect metal screw tooth outline, high measuring pitch, tooth, tooth inner shaft diameter, test the teeth machining defects.

The difficulty of the Project

Ordinary lens, because of the light Angle Angle is large, metal teeth at the edge Angle can produce spurious The light reflection effect, poor image sharpness, contour extraction precision is low.Screw tooth spiral structure makes the thread every point within the different object distance, normal lens are not guarantee that a spiral of feature points within the scope of the same effective depth of field, causing various imaging resolution is not in the same range, influencing the accuracy of detection.

The solution

Use BT series double telecentric lens.

Application advantages

High resolution, even with small pixel image sensor can also generate high resolution images, CFT is (the contrast transfer function) 70 lp/mm > 30%;

High heart, heart is far less than 0.1%, which is the core of the double telecentric lens, can completely avoid shadows caused by incident light Angle.

The depth of field is big, can be one-time perfect focus of different distance of the surface of the parts, general depth of field for the normal lens ten times the level.

Application development

For backlight detection of defects, the outline of the parts size and high precision requirements.Using a set of optics system to solve more than ordinary lens system to accomplish the different height of the gap between plane one test requirements.

Author：BTOS Editor