| 摘要 |
<p>The device is particularly useful for measuring the width of lines obtained by photogravure. It consists of a confocal optical system with a monomode light source producing a plane wavefront, an optical deflector (18, 20) to scan the line transversely, a component (26) that separates the incident beam directed towards the medium (12) carrying the line (13) from the beam reflected by the medium, and a detector. The detector consists of a knife whose edge (32) is located at the position conjugate to the focus of the lens in the optical system and transversely to the line whose width is to be measured, and a differential sensor (33), located at the position conjugate to the pupil and sensitive to the difference in the illumination on the two sides of the knife.
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