Patent ID: 9091855
Filing Date: 2015-07-28
Classification: G02B

Abstract:
1. An observation apparatus comprising: a beam splitter including a first observation optical system configured to observe an entire observation target; and a second observation optical system configured to magnify and observe a part of the observation target, the first and the second plane parallel plates each provided with a light reducing section in an area thereof through which neither the incident light incident from the first-and-third-face side onto the light splitting section nor transmitted light from the light splitting section to the second-and-fourth-face side pass, the light reducing section configured to allow T % of the incident light incident from the first-and-third-face side to pass therethrough to the second-and-fourth-face side, the beam splitter arranged so that the first and the third faces are opposed to the observation target; the transmitted light passed through the light splitting section and the transmitted light passed through the light reducing section are guided to the first observation optical system; and reflected light reflected by the light splitting section is guided to the second observation optical system.