CPC F21V 5/048 (2013.01) [F21V 5/008 (2013.01); F21V 5/045 (2013.01); F21V 7/0066 (2013.01); F21V 7/041 (2013.01); F21V 13/04 (2013.01); F21V 14/06 (2013.01); F21Y 2101/00 (2013.01); F21Y 2113/17 (2016.08)] | 5 Claims |
1. A lighting device comprising:
a light source configured to emit light in a punctiform manner;
a cup lens arranged at an emission side of the light source; and
a condenser lens arranged at an emission side of the cup lens, wherein the cup lens includes:
a bottom surface having a first outer shape and having a substantially circular shape,
a top surface having a second outer shape larger than the first outer shape and having a substantially circular shape, the top surface being at an emission side of and spaced apart from the bottom surface in an optical axis direction,
a side surface continuous with the bottom surface and the top surface, and
a recessed part having a substantially cylindrical shape, provided substantially at the center of the bottom surface, and accommodating the light source,
a sloped part sloping to the incident side from an outer peripheral part of the top surface toward the center, and
the cup lens is configured to spread light emitted from the sloped part outward from the optical axis,
the outer diameter size of the condenser lens is greater than the outer diameter size of the cup lens, and greater than the outermost diameter of incident light, which is the diameter of the incident region of the condenser lens of the light emitted from the outermost of the sloped part of the cup lens among the light emitted from the center of the light source when the distance between the cup lens and the condenser lens becomes largest within a predetermined distance of which the condenser lens is displaced with respect to the cup lens,
the outermost diameter of incident light becomes larger in accordance with the distance between the cup lens and the condenser lens within the predetermined distance,
the condenser lens is a Fresnel lens, and is supported movably in the optical axis direction with respect to the light source and the cup lens.
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