PURPOSE: To obtain an energy-saving-type electric illumination signboard which has no luminance nonuniformities and has a high luminous-flux maintenance rate by forming a reflection film made of calcium halophosphate on the inner wall of a glass tube, and forming a phosphor film over the reflection film.
CONSTITUTION: At first, 4.0g of calcium halophosphate which has an apatite structure and contains 0.01wt% of antimony is applied to the inner wall of a glass tube which has an outer diameter of 32mm and used for a 40 watt lamp, and dried so as to form a reflection film. Next, the reflection film is removed so that a 180° angle part of the opening part of the tube is coated with the reflection film. Then, after the reflection film is baked, 5.5g of a phosphor with daylight color is applied to the reflection film so as to form a phosphor film over the reflection film, and a fluorescent lamp (C) is made by a usual method. When the luminous-flux maintenance rates of the fluorescent lamp (C), a fluorescent lamp (d) prepared by using calcium halophosphate which has an apatite structue and contains no antimony, and a fluorescent lamp (e) which has a reflection film made of titanium dioxide are investigated simultaneously, they were all high, and almost no luminance nonuniformities were recognized in any of these three lamps (C), (d) and (e). When a half the usual number of such lamps (C) are used as sources for an electric illumination signboard, there is no luminance nonuniformities in the surface of the signboard, and the signboard has a high luminous-flux maintenance rate.
| WO/2009/135345 | COMPOUND HID ELECTRIC ARC TUBE |
| JPH09259831 | RARE GAS ELECTRIC DISCHARGE LAMP |
| JP2787821 | [Title of Invention] High Pressure Discharge Lamp |
OOTAKA YOSHINORI
SHIBATA HARUO
