Abstract: A compact self-ballasted fluorescent lamp has an arc tube in a double-spiral configuration, the arc tube being formed by bending a glass tube around an axis of spiral up to both ends of the glass tube, and a holder that is made of resin and holds this arc tube. Electrodes, each being equipped with a filament coil, are sealed at respective ends of the glass tube. The holder is made up of a holding resin member with a cylindrical shape having a closed bottom and a resin cover in a cone shape, the holder including a circumferential wall and an end wall that is at the edge of the circumferential wall. A heat-dissipating plate is provided inside the holding resin member, at a position corresponding to where the filament coils within the glass tube are.

Abstract: An objective is to provide a compact self-ballasted fluorescent lamp which can reduce occurrence of a short circuit without protecting lead wires extending from each end portion of a spiral arc tube. To achieve the objective, a pair of connection pins is provided on a circuit board of the compact self-ballasted fluorescent lamp, near a periphery of the circuit board so as to oppose another pair of connection pins formed near the periphery. In this way, the pairs of connection pins can be respectively provided directly above the end portions of the spiral arc tube. Thus, lead wires extending from each of the end portions can be connected to a corresponding one of the pairs of connection pins with a relatively short distance. This prevents the lead wires from being in contact with the circuit board, thereby reducing occurrence of a short circuit.

Abstract: This invention aims at providing a low-pressure mercury lamp having an improved luminous efficiency while maintaining the compactness and long life of the arc tube. This lamp comprises an arc tube formed by bending a glass tube. This arc tube is formed into a double-spiral structure comprising: a turning part located in substantially the midsection from both ends of the glass tube; a first spiral part starting from one of the ends and spiraling around the pivotal axis to reach the turning part; and a second spiral part starting from the turning part and spiraling around the pivotal axis to the other end. The glass tube has a circular shape in cross section with 7.4 mm inner diameter. This low-pressure mercury lamp is a 12 W lamp alternative to a 60 W incandescent lamp, and the bulb wall loading under steady state illumination is set at 0.103 W/cm2.

Abstract: A compact self-ballasted fluorescent lamp has an arc tube in a double-spiral configuration, the arc tube being formed by bending a glass tube around an axis of spiral up to both ends of the glass tube, and a holder that is made of resin and holds this arc tube. Electrodes, each being equipped with a filament coil, are sealed at respective ends of the glass tube. The holder is made up of a holding resin member with a cylindrical shape having a closed bottom and a resin cover in a cone shape, the holder including a circumferential wall and an end wall that is at the edge of the circumferential wall. A heat-dissipating plate is provided inside the holding resin member, at a position corresponding to where the filament coils within the glass tube are.

Abstract: An arc tube includes an arc tube body and a pair of electrodes. The arc tube body is formed from a glass tube which is double-spirally wound from a middle portion to both ends around a spiral axis. The pair of electrodes are sealed at both ends of the arc tube body. Mercury is enclosed in the arc tube substantially in a single form. Each of the electrodes includes a multiple-coiled filament which is wound substantially one turn in a last coiling stage.

Abstract: A compact self-ballasted fluorescent lamp includes an arc tube formed by a glass tube double-spirally wound from its middle to both ends around a spiral axis, and a cylindrical holding member having a closed bottom and holding the arc tube, a case fit to cover a circumferential wall of the holding member, and the like. End-vicinity parts of the glass tube are formed to have a larger gap with glass tube parts adjacent in the direction of the spiral axis. The arc tube is held in a state where the distance L1 between a first point that is on an outer surface of a glass tube part adjacent to one of the ends of the glass tube in the direction of the spiral axis and a second point on a surface of the end wall facing the first point is about 1.5 mm.