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US 4,381,136 AGranted
Method for covering ultraviolet sources
AssigneeRohm Co., Ltd.
InventorsLudwig Hosch, Guenther Ittmann
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AssigneeRohm Co., Ltd.
InventorsLudwig Hosch, Guenther Ittmann
Estimating the term…
Disclosed is a method for covering a source emitting ultraviolet radiation which method comprises covering said source with an acrylic glass colored with a coloring agent which absorbs in the visible region of the spectrum between 400 nanometers and 550 nanometers and exhibits an absorption of at least 2 percent for any wavelength within this region, and which agent concurrently has an average degree of transmission in the A- and B-region of the ultraviolet spectrum which is not below 55 percent and is not less than 10 percent at any wavelength in this region, said agent being present at a concentration equivalent to 0.0005 to 0.3 percent by weight in a layer, one millimeter thick, of a radiation absorbing matrix. Also disclosed are colored acrylic glass covers for use in such a method.
A method for covering a source emitting ultraviolet radiation which comprises covering said source with an acrylic glass colored with a coloring agent which absorbs in the visible region of the spectrum between 400 nanometers and 550 nanometers and exhibits an absorption of at least 2 percent for a wavelength within this region, and which agent concurrently has an average degree of transmission in the A- and B-region of the ultraviolet spectrum which is not below 55 percent and is not less than 10 percent at any wavelength in this region, said agent being present at a concentration equivalent to 0.0005 to 0.3 percent by weight in a layer, one millimeter thick, of a radiation absorbing matrix.
A cover for a source emitting ultraviolet radiation, said cover comprising an acrylic glass colored with a coloring agent which absorbs in the visible region of the spectrum between 400 nanometers and 550 nanometers and exhibits an absorption of at least 2 percent for a wavelength within this region, and which agent concurrently has an average degree of transmission in the A- and B-region of the ultraviolet spectrum which is not below 55 percent and is not less than 10 percent at any wavelength in this region, said agent being present at a concentration equivalent to 0.0005 to 0.3 percent by weight in a layer, one millimeter thick, of a radiation absorbing matrix.
Dependencies are inferred from the claim text.