Plastic substrate nd filter and plastic substrate nd filter for use in eyeglasses
AssigneeTokai Optical Co., Ltd.
InventorRyosuke Suzuki
Life of this patent
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Abstract
Provided are a ND filter and a spectacle ND filter that have a base made of plastic and that have excellent durability. The ND filter has a base made of plastic, and a light absorbing film having a plurality of layers is provided on at least one surface of the base. The light absorbing film includes one or more NiOx layers made of NiOx, x being not less than 0 and not greater than 1, and includes a sandwich structure portion which is provided on an opposite side of at least one of the NiOx layers from the base and in which a reverse stress layer is sandwiched between silica compound layers.
Claims11
A plastic base ND filter comprising:
- a base made of plastic;
- and
- a light absorbing film provided on at least one surface of the base and having a plurality of layers, wherein
- the light absorbing film
- includes one or more NiOx layers made of NiOx, x being not less than 0 and not greater than 1, and
- includes a sandwich structure portion which is provided on an opposite side of at least one of the NiOx layers from the base and in which a reverse stress layer is sandwiched between silica compound layers.
Dependencies are inferred from the claim text.