| 摘要 |
<p>@ A composite filter for intercepting light of a radiation spectrum in the region of 600-900 nm comprising at least one organic film filter and at least one glass filter, in which said organic film filter absorbs light of a radiation spectrum in the region of 600-700 nm and said glass filter absorbs light of a radiation spectrum in the region of 700-900 nm. An observation system for dark field utilizing a multi-channeled photomultiplier tube, which is provided with said composite filter is disclosed. Further disclosed is a filamentary display device containing plural bar-type coiling filaments encased in a casing having a transparent window portion in which said transparent window portion is provided with said composite filter.</p> |
