| 摘要 |
<p>The measurement device detects sloping edges running from the plank reference plane. This plane is illuminated and observed by a receiver, e.g. a camera, a device with a line of photodiodes and an optical lens (line scanning camera) etc. The plank (1) is examined by it, esp. for the shape of its edges. The plank is illuminated by a rectangular beam of light perpendicular to its longitudinal axis, moved along the plank. Its direction of incidence and of observation form an angle with the plank longitudinal axis, so that when planks with sloping edges are observed, a boundary between light and shade is visible, deviating from a straight line, bent in accordance with the sloping edges.</p> |
