Nippon Soda Co., Ltd.

Kanagawa Academy of Science and Technology

Tokuyoshi Saitoh

Akira Fujishima

Kazuhito Hashimoto

Tetsuo Yoshimoto

Shigemichi Fukayama

Tomokazu Iyoda

An illuminating device is made from a transparent hollow envelope that encloses a filler gas. The envelope has inner and outer surfaces. The illuminating device has a coating of a fluorescent material deposited on the inner surface of the transparent envelope where the fluorescent material emits light having a visible component and an ultraviolet component; and a titanium dioxide film having first and second opposing surfaces where the first surface of the titanium dioxide film is formed on the outer surface of the transparent envelope. A light transmittance of the titanium dioxide film is at least 50% for light having a wavelength of 550 nm, and the light transmitted from the fluorescent material through the transparent envelope and the first surface of the titanium dioxide film to the second surface thereof causes photocatalytic activity to be generated on the second surface of the titanium dioxide film.

Illuminating devices employing titanium dioxide photocatalysts

A titanium dioxide film () having at least photocatalytic activity, whose light linear transmittance corresponding to light having a wavelength of 550 nm is not less than 50% and whose thickness is 0.1 to 5 &#x3bc;m or so, is formed on a transparent substrate () constituted by a glass plate or the like. Preferably, a precoat film (), which has optical transmissivity and is constituted by a SiOfilm having a thickness of 0.02 to 0.2 &#x3bc;m or so, is provided between the transparent substrate () and the titanium dioxide film (). Thereby, excellent photocatalytic action and optical transmissivity can be obtained. Moreover, members composing various structures such as a glass window, which are especially required to have optical transparency, can be further provided with photocatalytic activities.

Window glass employing titanium dioxide photocatalyst

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Ichihara, Japan

Tokuyoshi Saitoh