| 摘要 |
<p>STONE DETECTOR An improved device for detection of stones in the sidewalls of glass containers. Stones in the sidewalls of glass containers cause stress patterns to be formed. These patterns are visible if the glass container is viewed through crossed polarizing filters due to the refraction of polarized light. A television camera and electronic analysis circuit may be substituted for the human eye. The detection capability and reliability of the system is improved if the glass container is illuminated with primarily infra-red radiation. Then, polarizing filters which polarize infra-red radiation and remove visible light are used. A filter before the television camera lens removes far infra-red radiation and allows only near infra-red radiation to be measured. This makes the device insensitive to glass color, flutes or stippling and improves the signal to noise ratio.</p> |
