Abstract: A reflection reducing film is provided on a surface of an optical substrate, and is sequentially provided with a buffer layer and a reflection reducing layer. The reflection reducing layer includes first to eighth layers sequentially laminated from the side of the buffer layer. The first and sixth layers are made of a low-refractive index material having a refractive index in the range of 1.35 to 1.50 at the d-line, the third, fifth and seventh layers are made of an intermediate-refractive index material having a refractive index in the range of 1.55 to 1.85 at the d-line, and the second, fourth and eighth layers are made of a high-refractive index material having a refractive index in the range of 1.70 to 2.50 at the d-line.

Abstract: A reflection reducing film is provided on a surface of an optical substrate, and is sequentially provided with a buffer layer and a reflection reducing layer. The reflection reducing layer includes first to eighth layers sequentially laminated from the side of the buffer layer. The first and sixth layers are made of a low-refractive index material having a refractive index in the range of 1.35 to 1.50 at the d-line, the third, fifth and seventh layers are made of an intermediate-refractive index material having a refractive index in the range of 1.55 to 1.85 at the d-line, and the second, fourth and eighth layers are made of a high-refractive index material having a refractive index in the range of 1.70 to 2.50 at the d-line.

Abstract: A curve representing a characteristic of a blue-light reflecting dichroic film DB and a curve representing a characteristic of a red-light reflecting dichroic film DR are configured to have shapes that track an ideal spectral characteristic of green. Accordingly, it is possible to obtain a characteristic approximated to the ideal spectral characteristic without using a trimming filter having a dichroic film in an exiting surface of a prism. Since it is not necessary to use the trimming filter having the dichroic film, it is possible to prevent ghost and flare from occurring due to the dichroic film of the trimming filter. Accordingly, it is possible to embody an imaging apparatus having the ideal spectral characteristic with ghost and flare being reduced.

Abstract: An antireflection film includes a multilayer film having six layers, in total, provided between an optical substrate and an adhesion layer. The respective layers of first to sixth layers are laminated in order from one side of the adhesion layer. A refractive index of the antireflection film as a whole is lower than that of the optical substrate and higher than that of the adhesion layer. The first and third layers are low refractive index layers having a refractive index of 1.35 to 1.50 at d line. The second, fourth and sixth layers are middle refractive index layers having a refractive index of 1.55 to 1.85 at the d line. The fifth layer is a high refractive index layer having a refractive index, at the d line, that is in a range of 1.70 to 2.50 and that is higher than that of the middle refractive index layer.

Abstract: An antireflection film is disposed on a surface of an optical substrate, and consists of first to tenth layers to stacked sequentially from the opposite side to the optical substrate. The first layer, the fourth layer and the ninth layer are low-refractive index layers made of a low-refractive index material exhibiting a refractive index of 1.35 to 1.50 with respect to the d-line. The third layer, the fifth layer, the seventh layer and the tenth layer are intermediate-refractive index layers made of an intermediate-refractive index material exhibiting a refractive index of 1.55 to 1.85 with respect to the d-line. The second layer, the sixth layer and the eighth layer are high-refractive index layers made of a high-refractive index material exhibiting a refractive index that is in a range from 1.70 to 2.50 with respect to the d-line, and that is higher than the refractive index of the intermediate-refractive index material.

Abstract: A reflection reducing film is provided on a surface of an optical substrate, and is sequentially provided with a buffer layer and a reflection reducing layer. The reflection reducing layer includes first to eighth layers sequentially laminated from the side of the buffer layer. The first and sixth layers are made of a low-refractive index material having a refractive index in the range of 1.35 to 1.50 at the d-line, the third, fifth and seventh layers are made of an intermediate-refractive index material having a refractive index in the range of 1.55 to 1.85 at the d-line, and the second, fourth and eighth layers are made of a high-refractive index material having a refractive index in the range of 1.70 to 2.50 at the d-line.

Abstract: A curve representing a characteristic of a blue-light reflecting dichroic film DB and a curve representing a characteristic of a red-light reflecting dichroic film DR are configured to have shapes that track an ideal spectral characteristic of green. Accordingly, it is possible to obtain a characteristic approximated to the ideal spectral characteristic without using a trimming filter having a dichroic film in an exiting surface of a prism. Since it is not necessary to use the trimming filter having the dichroic film, it is possible to prevent ghost and flare from occurring due to the dichroic film of the trimming filter. Accordingly, it is possible to embody an imaging apparatus having the ideal spectral characteristic with ghost and flare being reduced.

Abstract: An antireflection film includes a multilayer film having six layers, in total, provided between an optical substrate and an adhesion layer. The respective layers of first to sixth layers are laminated in order from one side of the adhesion layer. A refractive index of the antireflection film as a whole is lower than that of the optical substrate and higher than that of the adhesion layer. The first and third layers are low refractive index layers having a refractive index of 1.35 to 1.50 at d line. The second, fourth and sixth layers are middle refractive index layers having a refractive index of 1.55 to 1.85 at the d line. The fifth layer is a high refractive index layer having a refractive index, at the d line, that is in a range of 1.70 to 2.50 and that is higher than that of the middle refractive index layer.

Abstract: An antireflection film is disposed on a surface of an optical substrate, and consists of first to tenth layers to stacked sequentially from the opposite side to the optical substrate. The first layer, the fourth layer and the ninth layer are low-refractive index layers made of a low-refractive index material exhibiting a refractive index of 1.35 to 1.50 with respect to the d-line. The third layer, the fifth layer, the seventh layer and the tenth layer are intermediate-refractive index layers made of an intermediate-refractive index material exhibiting a refractive index of 1.55 to 1.85 with respect to the d-line. The second layer, the sixth layer and the eighth layer are high-refractive index layers made of a high-refractive index material exhibiting a refractive index that is in a range from 1.70 to 2.50 with respect to the d-line, and that is higher than the refractive index of the intermediate-refractive index material.