| 摘要 |
PURPOSE:To enable the luminous color to be varied within a certain range by lighting the low pressure discharge lamp which is coated with the mixed phosphor materials consisting of plural numbers of phosphor materials of different excitation sensitivity against respective ultraviolet rays and of different luminous color with the radiation strength ratio varying among the plural kinds of the ultraviolet ray. CONSTITUTION:Mixed phosphor materials consisting of phosphor A strongly the ultraviolet rays of 254nm and phosphor material B strongly sensing the ultraviolet rays of 185nm is applied on the tube wall internal surface of low pressure mercury discharge lamp radiating ultraviolet rays of 254nm and 185nm chiefly. And the lamp is lighted through an ignition device equipped with a control means to vary the radiation strength ratio of both ultraviolet rays relatively. Now, for example, the ignition mode is in D.C. lighting, it is made at the discharge condition radiating 254nm rays most properly, phosphor materials A, B are both fully excited and inherent color generation is performed. And when a little more phosphor material A and a little less phosphor material B are mixed beforehand, for example at the color degree table as shown, light color (warm white color) being at low color temperature 2,000-3,000 degrees K as a point (a) is obtained. |
