| 摘要 |
The principles of nonimaging optics, rather than imaging optics, are used to provide an asymmetrical flux extraction cup for an LED illumination lamp that has an asymmetrical limited viewing angle or cutoff angle. The cup has a flat section in the bottom normal to the optical axis, for attachment of the LED. In a cross section of one side of the cup, there is a circular section extending from the flat section to a lower point located at an intersection with a line from the opposite cup lip through a nearest edge point of a top surface of an envelope in which the LED is positioned. Next is a lower parabolic section extending from the lower point to an upper point located at an intersection with a projection of the top surface of the positioning envelope. The lower parabolic section has a vertex at the lower point, an axis projecting through the nearest edge point and the lower point, and a focus at the nearest edge point. Then there is an upper parabolic section extending from the upper point to the cup lip. The upper parabolic section has a vertex at the cup lip, an axis extending through the farthest edge point and parallel to the axis of the lower parabolic section, and a focus located at the farthest edge point of the top surface of the positioning envelope.
|
