SPOT LIGHT SOURCE AND BULB-TYPE LIGHT SOURCE
In a spot light source 1 including a case 11 , a heat radiator 12 and a light-emitter 18 , the heat radiator 12 is formed to have a bowl shape including a bottom portion 12 a and a side wall portion 12 b extending from the peripheral edge of the bottom portion 12 a , and the side wall portion 12 b is made of light-transmissive ceramic. Light emitted by an LED element 18 b of the light-emitter 18 is guided to the side wall portion 12 b by a lens 18 d so as to generate a leak light traveling sideways from the spot light source 1 , which produces highly decorative effect.
1 . A spot light source that serves as a substitute for a halogen light bulb having a reflection mirror, comprising:
a heat radiator being bowl-shaped and including a bottom portion and a side wall portion;
a light-emitting element provided within the heat radiator on the bottom portion;
an optical controller controlling light emitted by the light-emitting element;
a case having a built-in circuit for lighting the light-emitting element; and
a base supplying power to the built-in circuit, wherein
the optical controller guides a portion of the light emitted by the light-emitting element to the side wall portion, and
the side wall portion is light-transmissive.
2 . The spot light source of claim 1 , wherein
the side wall portion is made of ceramic.
3 . The spot light source of claim 2 , wherein
the ceramic contains primarily one or more constituents selected from the group consisting of silicon carbide, aluminum nitride, sapphire, alumina, beryllia, titania, yttria, silicon nitride, boron nitride, zirconia, magnesia and silica.
4 . The spot light source of claim 1 , wherein
the side wall portion contains a rare earth element in a polycrystalline state, and changes a color of the light from the light-emitting element.
5 . The spot light source of claim 2 , wherein
a silicon carbide film is formed on an external circumferential surface of the side wall portion.
6 . The spot light source of claim 1 , wherein
the side wall portion is made of a resin material.
7 . The spot light source of claim 1 , wherein
the bottom portion and the side wall portion are integrated in one piece.
8 . A bulb-type light source that serves as a substitute for a halogen light bulb having a reflection mirror, comprising:
a heat radiator being bowl-shaped and including a bottom portion and a side wall portion;
a light-emitting element provided within the heat radiator on the bottom portion;
an optical controller controlling light emitted by the light-emitting element;
a case having a built-in circuit for lighting the light-emitting element; and
a base supplying power to the built-in circuit, wherein
the optical controller guides a portion of the light emitted by the light-emitting element to the side wall portion, and
the side wall portion is made of ceramic containing a rare earth element in a polycrystalline state, and changes a color of the light from the light-emitting element.
9 . The bulb-type light source of claim 8 , wherein
the ceramic contains primarily one or more constituents selected from the group consisting of silicon carbide, aluminum nitride, sapphire, alumina, beryllia, titania, yttria, silicon nitride, boron nitride, zirconia, magnesia and silica.