APPARATUS AND METHOD PHASE SHIFTING STRIPE PATTERNS PROJECTION FOR DETECTING DEFECT OF TRANSPARENT OBJECT

摘要

The present invention provides a device and a method thereof to project a phase shift for detecting a fault of a transparent body. The device includes a projecting part (300) generating a dark field of a measurement object (210) and a correction surface by emitting grid image light to a measuring part (200); the measuring part (200) making the light, emitted from the projecting part (300), penetrate the measurement object (210), which is a transparent body; and an image obtaining part (100) receiving the light, penetrating the measurement object (210) in the measuring part (200), through a light receiving system (120) and obtaining an image from a camera (110), and detecting a fault of the measurement object (210) by using a Z map which is light and shade information of the dark field extracted from the image. Thus, as a repetitive latticed phase shift is formed and projection magnification is able to be adjusted, a fault of a fine object is found, and as every light beam passing through an LCD becomes incident along an optical axis of a light receiving part, light is effectively tested.