Patent ID: 6789919
Filing Date: 2004-09-14
Classification: F21S,F21Y,H01J,Y02B

Abstract:
A circular fluorescent lamp unit comprising:a glass bulb bent into a ring shape with both ends abutting on each other, said glass bulb having a tube outer diameter set within a range of 13 mm to 20 mm and having a ring outer diameter set within a range of 145 mm to 170 mm; mercury and inert gas sealed within said glass bulb; electrodes provided at respective ends in an inner space of said glass bulb; phosphor powder coated on an inner wall of said glass bulb; and a cap having connection pins used for electrically connecting said electrodes in said glass bulb with the outside and being attached so as to cut across said both ends of said glass bulb, wherein said circular fluorescent unit has a lamp wattage which is not greater than 20 W and used for lighting with high frequency which is not less than 10 kHz, said circular fluorescent lamp unit being suitable for illumination in a relatively narrow place with a system efficiency on the order of 61.0 lm/W while generating minimal heat.