| 摘要 |
<p>PURPOSE:To improve the operation efficiency of the visual field limiting stop by constituting variable stop plates of the visual field limiting stop by using a wavelength selective material which cuts infrared light and transmits only visible light. CONSTITUTION:The four variable stop plates 25 - 28 incorporated in the visual field limiting stop 11 are constituted by employing heat-ray absorbing filters. Therefore, even when a analytic sample piece 2 is observed through an ocular while the visual field limiting stop 1 is put in a stop-down state, a sample piece area part behind it can be observed. phosphate glass which is about 1mm thick is usable for the heat-ray absorbing filters used for the stop plates 25 - 28. The glass of the heat-ray absorbing filters is bluish, so while the sample piece is illuminated with light in visible observation mode, the border of the visual field range of the visual field limiting stop 11 can be discriminated clearly, which is convenient for the setting of an aperture. Consequently, setting operation for the aperture setting of the visual field limiting stop for an extremely small spectral measurement position specified on the sample piece is easily performed with efficiency.</p> |
