COMPACT HIGH BRIGHTNESS LED GROW LIGHT APPARATUS, USING AN EXTENDED POINT SOURCE LED ARRAY WITH LIGHT EMITTING DIODES

摘要

A compact high-brightness LED grow light fixture is described for use in growing plants under artificial light, or as a supplement to natural sunlight. The LED grow light uses a densely-packed array of high-brightness light emitting diodes (LEDs) that are not individually packaged where the array behaves similarly to a point source of light. The LED chips are distributed laterally over an area, where the LED chips have light emitting surfaces for emitting light in directions transverse to said area, wherein the dimensions of the area do not exceed 25 mm. Adjacent chips of the array are preferably separated by less than about 0.2 mm. The extended point source LED array, with its lens and associated reflector, result in a concentrated, partially-collimated light source, such that the intensity of the light does not diminish rapidly as distance from the light source increases. Thus, foliage that is lower down on the plant will receive almost as much light energy as does foliage on the top of the plant. The compact LED grow light does not block much of the natural sunlight, making the LED grow light suitable for use as a supplement to natural sunlight. The LED array contains a plurality of LED strings that may be separately controlled, thereby allowing the spectral content of the LED grow light to be varied, to facilitate desired plant growth at various stages of plant life. Multiple wavelengths of LEDs may be used within each LED string, thereby allowing the ability to further optimize the spectral content of the LED grow light. Due to the compact size of the LED grow light, the light emitted at each of the multiple different wavelengths from the array is evenly distributed, when the objects being illuminated by the array are at a distance of less than about 6 feet or even less than 1 foot from the array. Flexible mounting options allow for the use of multiple compact LED grow lights within a single plant growing area, and also allow for side or bottom lighting of plant foliage, in addition to the more typical overhead lighting.