Two-color mixing LED illuminating device

An LED illuminating device comprising:

• a housing comprising a base plate;
• a prism sheet mounted in the housing and comprising a light incident surface facing LED units and a light exit surface opposite to the light incident surface;
• wherein a plurality of V-shaped micro-grooves are formed on the light exit surface, the V-shaped micro-grooves extend along three directions and intersect with each other;
• a circuit board fixed on the base plate;
• and
• a plurality of LED units being alternately arranged on the circuit board;
• wherein the LED units comprise a plurality of first LED units emitting light of a first color and a plurality of second LED units emitting light of a second color, the second color is different from the first color, three second LED units are evenly arranged by a first preset distance around each of the first LED units;
• wherein each LED unit is configured to illuminate a portion of the prism sheet, the illuminated portion of the prism sheet includes six distinct light outputting portions each configured to output light originally from said LED unit, the six light outputting portions are distributed on a circle which has a center aligned with said LED unit, and the first preset distance is √{square root over (3)} times as long as the radius of the circle, so as to generate six virtual mixed light sources by combining the light emitted by the corresponding first LED unit and three adjacent LED units when the light enters the prism sheet, wherein each of the virtual mixed light sources has a color different from the colors of the light emitted from the first LED units and the second LED units.