Electrodeless discharge lamp

An electrodeless discharge lamp, comprising:

• a bulb filled with discharge gas;
• an induction coil for generating an electromagnetic field in the bulb;
• a power supply circuit which includes a plurality of electric components and which supplies electric power to the induction coil;
• a case for accommodating the plurality of electric components, the case having a surface which faces an external element of the electrodeless discharge lamp;
• a stick-shaped heat conducting member placed along a winding axis of the induction coil;
• a second heat conducting member thermally connected to the stick-shaped heat conducting member at a joint surface;
• and
• a third heat conducting member for thermally connecting at least two of the plurality of electric components,
• wherein the second heat conducting member is thermally connected to the case, and
• a product of the thermal conductivity of the stick-shaped heat conducting member and the area of a cross-section of the stick-shaped heat conducting member which is perpendicular to a central axis of the stick-shaped heat conducting member is smaller than a product of the thermal conductivity of the second heat conducting member and the area of the joint surface.

An electrodeless discharge lamp, comprising:

• a bulb filled with discharge gas;
• an induction coil for generating an electromagnetic field in the bulb;
• a power supply circuit which includes a plurality of electric components and which supplies electric power to the induction coil;
• a case for accommodating the plurality of electric components, the case having a surface which faces an external element of the electrodeless discharge lamp;
• a stick-shaped heat conducting member placed along a winding axis of the induction coil;
• a first planar heat conducting member placed so as to be perpendicular to the winding axis, the first heat conducting member being thermally connected to the stick-shaped heat conducting member;
• a second heat conducting member thermally connected to the first heat conducting member;
• a third heat conducting member for thermally connecting at least two of the plurality of electric components;
• and
• a printed circuit board on which the plurality of electric components are placed,
• wherein the second heat conducting member is thermally connected to the case,
• the third heat conducting member is thermally connected to the case, and
• there is a space between the printed circuit board and the second heat conducting member.

An electrodeless discharge lamp, comprising:

• a bulb filled with discharge gas;
• an induction coil for generating an electromagnetic field in the bulb;
• a power supply circuit which includes a plurality of electric components and which supplies electric power to the induction coil;
• a case for accommodating the plurality of electric components, the case having a surface which faces an external element of the electrodeless discharge lamp;
• a stick-shaped heat conducting member placed along a winding axis of the induction coil;
• a first planar heat conducting member placed so as to be perpendicular to the winding axis, the first heat conducting member being thermally connected to the stick-shaped heat conducting member:
• and
• a second heat conducting member thermally connected to the first heat conducting member,
• wherein the second heat conducting member is in contact with the case at a surface contact portion.