| 摘要 |
The invention is a digital sundial device, serving mainly for continuous visual time signalling and, in the sphere of astronomy and descriptive geometry, as an educational aid too. The device consists of: an index line (1) or index point, a (family of) transparent time scale(s) (2), and either a non-transparent or a translucent (semi-transparent) viewing screen (4) - the translucent one covering a transparent planparallel plate -, containing the index line (1) and/or the index point or their shadow, showing the (family of) bright wandering time scale(s) (3) projected by the sun beams through the (family of) transparent time scale(s) (2) and receiving the mark of the just valid point of time on the index line (1) itself, and members supporting, adjusting, and protecting the said geometrical formations (1, 2, 3, 4), among which, the index line (1) is erected parallel with the rotation axis of the Earth, the time marks (7) of the (family of) transparent time scale(s) (2) named by related signs (6) are distributed in a scale wall (16) so that the imaginary meridian semi planes (9) lying on the index line (1) and each containing one of the time marks either follow each other with a meridian angle (8) density of 15 /h=0,25 /min, or - in case of a non-negligible optical inhomogenity of the medium surrounding the device - with a meridian angle (8) density conform to the light refraction. |
