| 摘要 |
A lens member of obtaining light-collecting properties even if using a light source with a large light-emitting surface area has a first lens portion refracting light to exit outward in radial directions perpendicular to a central axis of the lens member and a second lens portion totally internally reflecting the light that exited through the first lens portion. The first lens portion has a light incident surface disposed to face a light source and a conical light exit surface centered at the central axis of the lens member and slanted so that the distance between the conical surface and the light incident surface increases as the distance from the central axis increases outward in the radial directions perpendicular to the central axis. The second lens portion has an inner circumferential surface receiving light from the first lens portion and an outer circumferential surface positioned outward of the inner circumferential surface in the radial directions perpendicular to the central axis. The outer circumferential surface totally reflects light received through the inner circumferential surface in a direction away from the first lens portion toward the second lens portion in parallel to the direction of extension of the central axis.
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