Endoscope objective has hollow volume filled with solid or liquid transparent filling material, e.g. glass or immersion material, especially immersion oil or gel

摘要

The objective has a lens group (1) with a negative lens (2) on the far side enclosing a hermetically sealed hollow volume (3) with the rest of the lens group. The hollow volume is filled with a solid or liquid transparent filling material, e.g. glass or an immersion material, especially an immersion oil or gel. The negative lens has a high refractive index and the filling material a low index.