Method for detecting defect of transparent body, method for producing transparent body
US6226080A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1999 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | Mar 23, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/958
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Defect of an acrylic plate is detected such that a light beam, which dominantly includes non-parallel rays not parallel to a principal surface of the acrylic plate, is introduced through a side surface formed substantially perpendicularly to the principal surface of the acrylic plate. In this arrangement, transmitted light, which is obtained through the principal surface of the acrylic plate on the basis of the defect, is detected by using any one of or both of a light-receiving device with its light-receiving surface arranged and directed substantially in parallel to the principal surface of the acrylic plate and a light-receiving device with its light-receiving surface arranged and directed substantially perpendicularly to the principal surface of the acrylic plate. Thus, the defect of the acrylic plate is quantitatively detected by measuring the amount of light of the transmitted light. Accordingly, an identical optical system can be used to perform the detection of, for example, the surface scratch of the acrylic plate as well as the bubble and the foreign matter in the acrylic plate simultaneously with the detection of the defect such as the bend and the waviness of the acryli…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.