Illuminating device

Abstract

Abstract PURPOSE:To obtain spot light of high luminance with low electric power consumption, by using the light radiated from a lamp without waste. CONSTITUTION:The light radiated in all directions from a lamp 11 is classified to any of the light L10 incident to a parabola reflection plate 10, the light L20 incident to a spherical reflection plate 12 and the light L30 passing through an opening 12a. When the light L10 among these is reflected by the plate 10, it forms the light L11 parallel with an optical axis 15 and is made incident to a concave lens 13 through the opening 12a. When the light L20 is reflected by the plate 12, it forms the light L21 incident to the plate 10 hence the light L22 parallel with the axis 15. Said light is made incident to the lens 13 through the opening 12a. The reflected light L11, L22 parallel with the axis 15 are diffused like the light emitted from the focus of the lens in the stage of passing through the lens 13. In contrast with the same, the light L30 out from the focus of the lens 13 advances rectilinear as it is in the lens; therefore all of the light L30', L22', L11' on the exit face 13a of the lens 13 constitute a part of the luminous flux radiating in a circular cone shape around the lamp 11.

Inventors

• 👤 Tadashi Nagahara
• 👤 永原　忠志

Bibliographic Details