| 摘要 |
PURPOSE:To improve the mechanical strength of the curved section of a Ushaped glass bulb without damaging the condensation function of mercury of setting the curved section of the U-shaped glass bulb to almost a triangular form whose cross section has the larger diameter than the straight line section and specifying an angle from the vertical angle section to the straight line section. CONSTITUTION:A glass bulb 1 that is curved in a U-shaped form is comprised with a straight line section 2 and a curved section 3. The curved section 3 is formed into a triangular shape so that one vertical angle section 3a can be located at an external circumference section and an opposed bottom section can be located at an internal circumference section. Simultaneously, the tilting angle of an inclined section 3c at the external circumference section from the vertical angle section 3a to the straight line section 2 is suppressed within the ranges of 15 to 40 degrees and the relationship between the outer diameter D1 of the straight line section 2 and the outer diameter D2 of the curved section 3 is set to D2>=1.5D1. Then, a U-shaped fluorscent lamp i formed using this glass bulb. As a result, an ample optical output can be obtained by using the vertical angle section 3a as the coolest section and the strength can be improved by suppressing the malleability glass at curved processing. |
