Patent ID: 8579472
Filing Date: 2013-11-12
Classification: F21V,F21Y,G02B

Abstract:
1. An illumination lens on which light radiated from a light source is incident and which controls distribution of the incident light to emit, the illumination lens comprising: an incidence surface through which the light radiated from the light source is incident on an interior of the illumination lens; a reflection surface which reflects part of the light incident on the interior of the illumination lens from the incidence surface, toward an illumination direction; and an emission surface which emits the light from the incidence surface and the reflection surface, toward the illumination direction, wherein: the incidence surface comprises an opening portion which is formed on a side on which the light source is arranged such that the light from the light source can enter, and a first incidence surface and a second incidence surface which are formed in an inner surface of a concave portion dented in a direction opposite to a direction in which the light source is arranged; the first incidence surface is arranged in a bottom surface of the concave portion and comprises a convex surface on the light source side to condense the light from the light source; the second incidence surface is an inside surface formed in a surrounding of an optical axis of the illumination lens in the convex portion such that the light from the light source can transmit toward the reflection surface; the reflection surface is a total reflection surface which totally reflects the light incident on the interior of the illumination lens from the second incidence surface, toward the illumination direction; the emission surface comprises a first emission surface which comprises a center portion intersecting the optical axis, and a second emission surface which is arranged in a surrounding of the first emission surface; the first emission surface is formed as a concave or convex surface; a refracting power of light in the second emission surface comprises zero or a different sign from a refracting power of light in the first emission surface; the light incident from the first incidence surface is emitted from the first emission surface; and part of the light reflected on the reflection surface is emitted from the second emission surface and other part is emitted from the first emission surface, in which a relationship between degrees of a first beam amount which is a beam amount of the light which is incident from the first incidence surface and emitted from the first emission surface, a second beam amount which is a beam amount of the light which is reflected on the reflection surface and emitted from the second emission surface and a third beam amount which is a beam amount of the light which is reflected on the reflection surface and emitted from the first emission surface is second beam amount > third beam amount > first beam amount.