| 摘要 |
The invention relates to a high-resolution objective for stereomicroscopes of the telescope type. In the case of stereomicroscopes of this type, it is often a matter, on the one hand, of meeting the need for an improved overview of the entire object during inspection but, on the other hand, of being able to view even the smallest details of the object. Specially designed objectives are required for this purpose. The objective according to the invention comprises two groups of lenses G1 and G2 each with a positive refractive power and a third group of lenses G3 with a negative refractive power. It is characterized by the following features: - total focal length f in the range of from 35 mm to 22 mm, - working distance in the range of from 0.2 to 0.45 times the total focal length f, - EP/f=0, 6...0, 95 where EP is the diameter of the entrance pupil at maximum magnification and f is the total focal length, - Y/f = tan? > 0, 16 where ? is the field angle, Y is the maximum diameter of the object field at minimum magnification and f is the total focal length, - resolution capability in the range of from 1000 Lp/mm to 1700 Lp/mm (Lp = line pairs). |
