| 摘要 |
In order to correct errors in the reading of a graduated scale, especially on a compass card driven by a damped gyroscopic system, the scale is juxtaposed with a block having slits simultaneously alignable with different scale graduations and illuminable by respective light sources within the block. The light sources can be selectively energized by a rotary switch whose bank contacts are connectable via a changeover switch to either of two groups of light sources for positive or negative deviations from a reference position; the slit so illuminated serves as a pointer by coacting with a confronting scale graduation.
|
