| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an observation optical device enabling observation in a narrow space, and a contact angle meter.SOLUTION: An observation optical device 1 includes: a first reflection surface 32 and a second reflection surface 42 that are disposed to face each other and have areas gradually coming closer to each other towards an observation object 10 side; a light source 10 that is disposed at such a position that light L emitted by itself and reflected by the first reflection surface 32 and the second reflection surface 42 at least once for each, is illuminated towards the observation object 100; and a lens optical system 22 that is disposed at such a position that the light L illuminated towards the observation object 100 and reflected by the first reflection surface 32 and the second reflection surface 42 at least once for each, enters.</p> |
