Method and apparatus for optical inspection
US5699153A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1995 |
| Grant date | Dec 16, 1997 |
| Priority date | — |
| Expiry date | Oct 31, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/4735
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides an inspecting method and an apparatus therefor. A light illuminates an object to be inspected having optical diffusive characteristics such as a ceramics plate. A part of the light diffuses in the object from an illumination area is reflected at or passes through a defect such as a crack and reaches an imaging area. An image sensor detects the image of the imaging area. A signal showing a larger change is processed thereby to inspect the defect. The object is displaced stepwise relative to the light source and the image sensor. Thus, a crack or the like in an object can be inspected with high accuracy and at a high speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.