Patent ID: 9065994
Filing Date: 2015-06-23
Classification: G02B,G03B,H04N

Abstract:
1. An image pickup apparatus, comprising: a filter unit configured to adjust a light amount of incident light from an image pickup optical system; a photoelectric transducer configured to perform photoelectric conversion of the incident light from the filter unit; and a light guide optical system configured to guide the incident light from the filter unit to the photoelectric transducer, wherein: the filter unit comprises a transmittance variable element configured to adjust a transmittance of the incident light; the light guide optical system comprises a color separation optical system comprising, in order from an object side, a first prism provided with a first dichroic film, a second prism provided with a second dichroic film, and a third prism, so as to separate the incident light into red color light, green color light, and blue color light to exit; one of the first dichroic film and the second dichroic film is a blue reflection dichroic film having a characteristic of reflecting the blue color light; and a rotational position of the transmittance variable element about an optical axis is such a position that a ratio of a transmittance for the blue color light to a transmittance for the green color light of a marginal ray entering the blue reflection dichroic film at an incident angle smaller than an incident angle of a principal ray of an axial ray to the blue reflection dichroic film is smaller than a ratio of the transmittance for the blue color light to the transmittance for the green color light of the principal ray of the axial ray.