| 摘要 |
<p>The probe for the density measurement of coloured photographic negatives has a cosine factor correction incorporated. The probe consists of a support member (1) typically a night angled prism, into the right angled vertex of which a cylindrical hollow is introduced containing a hollow cylinder (2), with a flat upper surface against which a flat plate (4) is fixed by a screw (5). Both the plate and the hollow cylinder have matching oblong slots (12) which enable the incident light beam (13) to enter a small 45 deg. angled prismatic reflector (6) which directs a reflected beam along the longitudinal axis of an optical fibre (9) which is rotatable in the hollow cylinder, being retained by the tip of a long screw (11) fitting into a groove. As the negative under test in contact with the plate (4) tilts, the cylinder (2) rotates to correct the cosine factor otherwise introduced.</p> |
