Lamp with variable-beam output by discretely activating LED light sources
First Claim
Patent Images
1. A light source producing a beam of variable divergence, comprising:
- a plurality of light-emitting devices arranged on a plane that includes a first set of light emitting devices positioned around a second set of light emitting devices;
a concave reflecting optic having an axis of symmetry traveling through the second set of light emitting diodes, and comprising a plurality of segments for reflecting at least a portion of light emitted by the light-emitting devices and reflected by the optic forming a light beam, the segments having an aiming angle which increases gradually with increasing distance from the plane of the plurality of light emitting devices for increasing light divergence of the light beam; and
driver circuitry for controlling drive currents to the light-emitting devices such that a maximum divergence of the light beam is produced by said driver circuitry powering outermost light emitting devices of the first set of light emitting devices, and a gradually decreasing divergence of the light beam is produced by said driver circuitry decreasing a number of powered outermost light emitting devices of the first set of light emitting devices while selectively powering a combination of the inner light emitting devices of the first set of light emitting devices and the second set of light emitting devices.
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Abstract
Lamp including an array of LEDs disposed at or near the focus of a reflecting optic having multiple segments with different aiming angles (i.e. the angle corresponding to a reflected beam output direction), and a driver circuit for discretely activating some of the LEDs in the array. The angular distribution of the output light beam (e.g., the beam divergence) is adjusted by selectively changing the currents supplied to the LEDs.
49 Citations
31 Claims
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1. A light source producing a beam of variable divergence, comprising:
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a plurality of light-emitting devices arranged on a plane that includes a first set of light emitting devices positioned around a second set of light emitting devices; a concave reflecting optic having an axis of symmetry traveling through the second set of light emitting diodes, and comprising a plurality of segments for reflecting at least a portion of light emitted by the light-emitting devices and reflected by the optic forming a light beam, the segments having an aiming angle which increases gradually with increasing distance from the plane of the plurality of light emitting devices for increasing light divergence of the light beam; and driver circuitry for controlling drive currents to the light-emitting devices such that a maximum divergence of the light beam is produced by said driver circuitry powering outermost light emitting devices of the first set of light emitting devices, and a gradually decreasing divergence of the light beam is produced by said driver circuitry decreasing a number of powered outermost light emitting devices of the first set of light emitting devices while selectively powering a combination of the inner light emitting devices of the first set of light emitting devices and the second set of light emitting devices. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method of varying a divergence of a light source comprising (i) a plurality of light-emitting devices arranged on a plane and in a pattern having a center region and an outer region outside the center region, (ii) a concave reflecting optic having an axis of symmetry and a plurality of segments, each segment having an aiming angle with respect to the axis of symmetry for redirecting light emitted thereon, the concave reflecting optic including a portion of the plurality of segments having a gradually increasing aiming angle with increasing distance from the plane of the plurality of light emitting diodes for increasing light divergence, and (iii) a driver circuitry for selectively controlling a drive current supplied to the light emitting devices, the method comprising:
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driving the light-emitting devices to create a light beam emerging from the reflecting optic; and controlling the divergence of an output beam of the light source by the driver circuitry controlling drive currents to the light-emitting devices based on distances of the devices from the axis of symmetry, wherein a maximum divergence of the output beam is produced by supplying a drive current to the light emitting devices outermost from the axis of symmetry, and an output beam with a gradually decreasing divergence is produced by selectively supplying a drive current for decreasing a number of powered outermost light emitting devices while powering light emitting devices closer to the axis of symmetry. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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Specification