Photosensitive pigment - Photochromic

In a broad sense, it refers to a dye that is affected in some way by light or that exerts other effects. Dyes that exhibit photochemical changes, such as dyes that exhibit photochromism, are examples. In a narrow sense, it refers to a dye that absorbs light and exhibits a spectral sensitizing or desensitizing effect in silver halide photography or electrophotography. In addition to their photographic function, they often exhibit physiological activity and have applications in the fields of medicine and agriculture. They are also used as dyes for laser light oscillation. Many of them are substances with large conjugated pi electron systems, and cyanine dyes are representative. [See alternative term] Sensitizing dye

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

広義には，光によりなんらかの作用を受けるか，ほかに作用を及ぼす色素をいう．光化学変化を示す色素，たとえばホトクロミズムを示す色素は，その例である．狭義には，光を吸収して，ハロゲン化銀写真や電子写真の分光増感作用，または減感作用を呈する色素をいう．写真作用のほか生理活性を示すことが多く，医療，農芸方面への応用もある．また，レーザー光発振用色素としても用いられる．その多くは大きな共役π電子系をもつ物質で，シアニン系色素が代表的である．[別用語参照]増感色素

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