CONDENSING ELEMENT AND FORMING METHOD THEREFOR AND CONDENSING ELEMENT-CARRYING LED LAMP AND LINEAR LIGHT EMITTING DEVICE USING LED LAMP AS LIGHT SOURCE

摘要

A condensing element or the like comprising a condensing unit having a translucent recessed end face having a curvature similar to that of the translucent protruding face of an LED lamp having an LED chip and the almost semi-spherical translucent protruding face surrounding the LED chip, and extending in a parabolic rotation body shape from the peripheral edge of the translucent recessed end face, characterized in that, as viewed at a section including the rotation axis of the condensing unit, an inclination, with respect to the rotation axis, of a tangent drawn to the condensing unit at the peripheral edge position of the translucent recessed end face is so set that an incidence efficiency of light emitted from an LED lamp to the condensing unit is at least a specified value.