Electronic flash, electronic camera and light emitting head
The present invention is directed to a light emitting head for use with an electronic camera. The light emitting head is preferably formed as an array of red, green, and blue light emitting diodes (LEDs) provided on the sides of a light guide member, preferably a polygonal prism. A reflecting mirror is arranged on the bottom of the prism, and reflecting elements are provided on the sides of the prism that are not in contact with the LEDs such that, in operation, light from the LEDs is emitted through the top of the prism and prevented from leaking through the sides. A diffusion plate is provided on the emission surface, and the number of green LEDs is larger than the number of red and blue LEDs to produce a white light. In other embodiments, the light guide member is a cylinder or formed entirely as a diffusion plate.
1. A method of emitting white light from a light emitting head, comprising the steps of:
providing substantially transparent light guide member having a top face, a bottom face, and at least one side face;
providing at least one light emitting device in contact with said at least one side face;
providing a reflecting mirror in contact with the bottom face;
providing reflecting mirrors in contact with surfaces of said at least one side face which are not in contact with said at least one light emitting device; and
emitting light of a plurality of different colors from said at least one light emitting device into said light guide member;
whereby white light is emitted through the top face.
2. A light emitting apparatus comprising:
a substantially transparent light guide member;
at least one light emitting element provided in contact with a face of said light guide member such that the light emitted from said light emitting element is transmitted through the face of said light guide member; and
a light reflecting element provided on at least a side of said light guide member not provided with a light emitting element;
wherein the faces of said light guide member which are provided with a light emitting element are further provided with a light reflecting element disposed in contact with surfaces of the faces which are not in contact with a light emitting element, and
wherein light emitted by said light emitting element propagates from said light guide member through a light emission surface of said light guide member opposite said light reflecting element.
3. The light emitting apparatus of claim 2 , wherein said light guide member comprises a substantially solid member.
4. The light emitting apparatus of claim 3 , wherein said light guide member is a diffusion plate.
5. The light emitting apparatus of claim 3 , further comprising a diffusion plate provided on the light emission surface of said light guide member.
6. The light emitting apparatus of claim 3 , wherein said light guide member is a polygonal prism.
7. The light emitting apparatus of claim 6 , wherein said light guide member is a rectangular prism.
8. The light emitting apparatus of claim 3 , wherein said light guide member is a cylinder.
9. The light emitting apparatus of claim 2 , further comprising a plurality of light emitting elements, wherein each of said light emitting elements is provided in contact with a different face of said light guide member.
10. The light emitting apparatus of claim 9 , wherein said light emitting elements are comprised of LEDs.
11. The light emitting apparatus of claim 10 , wherein said LEDs comprise red, blue, and green LEDs.
12. The light emitting apparatus of claim 11 , wherein the number of green LEDs is greater than the number of red LEDs and also greater than the number of blue LEDs.
13. The light emitting apparatus of claim 12 , wherein said LEDs consist of a red LED, a blue LED, and first and second green LEDs.