RETICLE FOR A TELESCOPE

摘要

The invention relates to a reticle with a visible pattern in a transparent substrate for a telescope. The pattern of the reticle is made of open grooves which are engraved in a surface of the transparent substrate, wherein the engraved open grooves define groove surfaces at an angle to said substrate surface in which the open grooves are engraved. The groove surfaces have a surface roughness which is large enough to scatter light directed onto the reticle perpendicular to the substrate surface when the reticle is illuminated in transmission mode, such that the pattern becomes visible relative to the remaining substrate surface by said light scattering at the groove surfaces in the transmission mode when viewed from a direction perpendicular to the substrate surface. The reticle is produced with direct laser engraving of the grooves.