Fluorescent lamp and manufacturing method for arc tube

A fluorescent lamp comprising:

• an arc tube that is formed by a bent glass tube;
• a pair of electrodes to provide a single discharge path within the arc tube;
• a globe that covers the arc tube;
• and
• a heat-conductive member that is provided between a part of the arc tube and the globe for conducting heat from the arc tube to the globe,
• wherein a cross section of the glass tube at an inner circumference thereof is in a non-circular shape,
• the arc tube is spiral in which the glass tube is spirally wound around an axis, and
• a first diameter of the cross section at the inner circumference is smaller than a second diameter of the cross section at the inner circumference, the first diameter being in a direction substantially perpendicular to the axis, the second diameter being in a direction substantially parallel to the axis wherein the heat-conductive member is at a most distant part along the axis of the spiral tube from the pair of electrodes and is substantially at a middle of the discharge path.

An arc tube for a fluorescent lamp, the fluorescent lamp comprising:

• the arc tube formed by a spirally bent glass tube;
• a globe that covers the arc tube;
• and
• a heat-conductive member that is provided between a part of the glass tube and the globe for contacting and conducting heat from the arc tube to the globe,
• wherein the glass tube encloses a pair of electrodes to provide a simple discharge path,
• the part of the glass tube in contact with the glass tube is at a most distant part along an axis thereof from the pair of electrodes and is substantially at a middle of the discharge path, and,
• mercury is enclosed in the glass tube in at least one of (a) a substantially single form, and (b) an amalgam form whose mercury vapor pressure characteristics at lighting are substantially equivalent to mercury vapor pressure characteristics of mercury in a single form at lighting, and
• the glass tube has a substantially circular-shaped cross section, and has an inner diameter in a range of 5 to 9 mm inclusive.

A fluorescent lamp comprising:

• an arc tube that is formed by a bent glass tube having a spiral configuration and in which mercury is enclosed;
• a pair of electrodes to provide a single discharge path within the arc tube;
• a globe that covers the arc tube;
• and
• a heat-conductive member that is provided between a part of the arc tube and the globe for contacting and conducting heat from the arc tube to the globe,
• wherein the arc tube encloses a pair of electrodes thereon,
• the mercury enclosed in the arc tube is in at least one of (a) a substantially single form, and (b) an amalgam form whose mercury vapor pressure characteristics at lighting are substantially equivalent to mercury vapor pressure characteristics of mercury in a single form at lighting,
• the part of the arc tube, contacting the heat-conductive member, which is in contact with the globe, is at a most distant part along an axis of the glass tube from the pair of electrodes and is substantially at a middle of the discharge path,
• the glass tube has a substantially circular-shaped cross section, and has an inner diameter in a range of 5 to 9 mm inclusive, and
• a temperature of a connection point between the arc tube and the globe, during lighting of the fluorescent lamp, is within a range of 60° C. to 65° C.