| 摘要 |
The present invention provides an instrument adapted for alignment with a light beam, which instrument includes an instrument body having a point of entry of the light beam, a light conducting channel, and a sensing element carried by the instrument and being spaced from the point of entry of the light beam. The sensing element serves to provide indication of alignment or misalignment between the instrument and the light beam. The light beam travels inside the instrument along the light conducting channel extending from the point of entry to the sensing element. One or more light guiding devices are disposed inside the light conducting channel to increase precision of alignment between the instrument and the light beam. The light guiding device has a wall forming a guiding passage inside the guiding device. When disposed inside the instrument, the wall of the guiding device blocks non-aligned light beams from reaching the sensing element, while allowing the aligned light beams to propagate along a predetermined path through the guiding passage inside the instrument and reach the sensing element. |
