Patent ID: 8425083

Claim:
A LED directional illumination energy-saving luminaire, characterized in that, it comprises: a plane circuit board with an X direction and a Y direction defined; and illumination units comprising a plurality of LEDs mounted to said circuit board in a tilted state with LED bodies thereof being positioned at a predetermined height from the plane circuit board, and said plurality of LEDs are arranged at intervals in an array along said X direction and said Y direction and are symmetrically distributed with respect to the center of said array, each of said LEDs is deviated by a predetermined angle with respect to said X direction and said Y direction, thereby allowing said illumination units having predetermined projection angles in said X direction and said Y direction, respectively; said illumination units comprise a first illumination unit located in the middle area of said circuit board and second illumination units that are symmetrically arranged at both sides of said first illumination unit, each of said illumination units comprises a plurality of LEDs mounted to said circuit board in a tilted state with LED bodies thereof being positioned at a predetermined height from the plane circuit board, said plurality of LEDs of each of said illumination units are arranged in an array with predetermined intervals therebetween along said X direction and said Y direction and are symmetrically distributed with respect to the center of said array, each of said LEDs is deviated by a predetermined angle with respect to said X direction and said Y direction, thereby allowing said illumination units having predetermined projection angles in said X direction and said Y direction, respectively; the slantwise angle α n of each of said LEDs as viewed in the section which is perpendicular to the plane circuit board and extends along said X direction, is governed by the following formula: α n =arc tangent(tangent55 degrees·( n− 0.5)/( N/ 2−0.5)) wherein: N is the total columns of said LEDs arranged along said X direction, and n is the sequence number of the column within which said LED is located, counted in the order from the center of the array of the LEDs towards the outside along said X direction; and the slantwise angle β m of each of said LEDs as viewed in the section which is perpendicular to the plane circuit board and extends along said Y direction, is governed by the following formula: β m =arc tangent( W ·( m− 0.5)/ M/H ) wherein: W is the illumination width of said luminaire along said Y direction, M is the total rows of said LEDs arranged along said Y direction, m is the sequence number of the row within which said LED is located, counted in the order from the center of the array of the LEDs towards the outside along said Y direction, and H is the mounting height of said luminaire.