| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a thin film ND filter capable of uniformly attenuating light volume in a visible range, and the area of which is divided into multiple densities. <P>SOLUTION: The ND filter 0 is composed of a transparent substrate 1 and a multilayer structure of light absorbing films 23, 25 and dielectric films 22, 24, 26, and is provided with a predetermined transmission density. Also, the filter is composed of a first optical film 2 formed on either one face of the transparent substrate 1 and the multilayer structure of light absorbing films and dielectric films, and is provided with the predetermined transmission density. The filter is at least provided with a second optical film 3 formed on either one face of the transparent substrate 1. The second optical film 3 is patterned at least, and there are formed a single film area (D=0.5) where the first optical film 2 and second optical film 3 are not overlapped planarly, and a double film area (D=1.0) where the first optical film 2 and second optical film 3 are overlapped planarly. The transmission density of the single film area is different from that of the double film area. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
