| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain an optical filter which has high absorption in a near IR region, is chemically stable and has excellent near IR absorption performance, heat ray absorbability, visible ray transmission performance, and light resistance. <P>SOLUTION: The optical filter has at least a near IR absorptive filter layer on a transparent support. The filter layer of the optical fiber contains the near IR dyestuff expressed by general formula (I) (in the formula (I), Y<SP>1</SP>, Y<SP>2</SP>, Y<SP>3</SP>, and Y<SP>4</SP>respectively independently denote hydrogen atoms, aliphatic groups, aryl groups or heterocyclic groups; X<SP>0</SP>and X<SP>1</SP>denote respective atoms of oxygen, sulfur, selenium or tellurium; Z<SP>0</SP>and Z<SP>1</SP>denote the atomic groups necessary for forming a specific pyran derivative; L denotes a methine group; p and q denote 0, an integer from 1 to 3; r denotes 5 or 7, respectively; A<SP>-</SP>denotes the pair anion existing when the neutralization of an electric charge is necessary; m denotes 0 or 1). <P>COPYRIGHT: (C)2004,JPO |
