| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a luminous tube capable of achieving a longer life and higher brightness even when the temperature of an upper region in an internal surface of a tube portion tends to rise and even when the temperature of a lower region in the internal surface of the tube portion tends to rise. <P>SOLUTION: The luminous tube satisfies (L<SB>C</SB>-L<SB>A</SB>)=(L<SB>D</SB>-L<SB>B</SB>) and L<SB>A</SB>≠L<SB>B</SB>assuming that an intermediate position between a pair of electrodes 42, 52 is a point P, the lowermost position relative to gravity in the internal surface of a tube unit 30 is a point A and the uppermost position is a point B, the lowermost position relative to gravity in an external surface of the tube unit 20 is a point C and the uppermost position is a point D, a distance from the point P to the point A is L<SB>A</SB>, a distance from the point P to the point B is L<SB>B</SB>, a distance from the point P to the point C is L<SB>C</SB>, and a distance from the point P to a point D is L<SB>D</SB>. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
