Method of reading optical image of inspected surface and image reading system employabale therein
US5197105A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1991 |
| Grant date | Mar 23, 1993 |
| Priority date | — |
| Expiry date | May 29, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/95653
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A set of red light sources (111-113) are provided above a printed board (20). One (111) of the light sources located in the angular aperture of an imaging lens system (140). The red light is applied to the printed board and reflected on a wiring pattern (22) provided thereon. Another light source (120) is provided under the printed board, and emits infrared light to the back surface of the printed board. The infrared light passes through a through hole (25) formed in the printed board and then enters the imaging lens system together with the red light reflected. Compound light consisting of the red light and the infrared light passes through the imaging lens system and is then splitted into the red light and the infrared light at a cold mirror (150). The respective lights are detected by image sensors (161, 162), to thereby obtain respective images of the wiring pattern and the through hole.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.