| 摘要 |
The optical scanner uses a unique compound optical system for processing reflected radiation in a manner to reduce the variations caused by changing position of a scanned substrate in a guideway. Two sources of radiation are directed at similar angles to the surface to be screened and the radiation is distributed over a larger area. Changes in position of the substrate in the guideway change the actual area reflecting the radiation sensed by the sensor, but the size of the reflecting area does not appreciably change. Any change effects both radiation systems in a similar manner. |
