Inspection device for defect inspection

Abstract

The present invention comprises an inspection method for transparent or reflective inspection objects, by using a retroreflective plate as a convex lens or concave mirror in such a way that defects can be detected in a stable fashion even if the inspection object is curved or if vibration occurs during movement of the inspection object; in which displacement of parallel light passing through or reflected in a measurement field is captured by using changes which occur in an inspection field, namely changes in the density gradient in the case of transmission inspection or in the reflection angle in the case of reflection inspection.; The present invention also comprises an inspection device for defect inspection, in which a knife edge is provided, horizontally to the optical axis, on the front surface of a camera lens for collecting the transmitted light or reflected light, in such a way that three-dimensional defect images can be obtained since any light which diverges from the parallel light is blocked with consequent changes in the contrast of the light due to the density gradient in the inspection field at the camera.

Description

technical field [0001] The present invention relates to inspection equipment for inspecting defects such as air bubbles, minute deformations, foreign matter, voids, etc. formed in or on an inspection object such as an opaque or transparent thin plate. More particularly, the present invention relates to an inspection apparatus including a knife edge and a retroreflective plate to stably provide clear images of defects even when an inspection object is subjected to vibration or has curved portions. Background technique [0002] figure 1 A planar light beam is shown incident on an upwardly or downwardly curved reflective plate in a general reflector optical system. [0003] figure 1 The left side of shows the optical path formed by the detection object bent upwards at one end, and figure 1 The right side of the shows the optical path formed by the detection object bent down at one end. [0004] Such as figure 1 As shown on the left side of , when a planar light beam is emi...

AI Technical Summary

Problems solved by technology

[0011] In this way, when the luminance rapidly changes to 0 luminance units on dark areas and 2 luminance units due to defect 11 on bright areas, an accurate image of defect 11 cannot be obtained because the bright areas are closely aligned with the dark areas. There's this very steep brightness gradient between regions

That is, such a rapid brightness change does not provide a brightness gradient, and only forms the outline of the defect 11 on the screen 9, thereby making it difficult to recognize the actual shape of the defect 11

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