| 摘要 |
A photoelectric length or angle measuring system for measuring the relative position of two objects includes a graduation of a scale which is scanned by a scanning plate of a scanning unit. The scanning unit includes an illuminating unit for the illumination of the graduations of the scale and the scanning plate. In this illuminating unit there is arranged a light emitting diode on a surface of a carrier. For the improvement of the light radiating characteristics of the illuminating unit, reflections in the direction of the graduations of the scale and the scanning unit of light beams emerging laterally from the light emitting diode are avoided by properly configuring the surface of the carrier. In alternate embodiments, this surface of the carrier consists of a light absorbing material, is covered by a light absorbing material, or is provided with a dimension along the measuring direction no greater than that of the light emitting diode.
|
