摘要:
Techniques are disclosed for obtaining a desired luminance and/or intensity distribution from any lighting fixture that is illuminated by a lightguide. The techniques can be used, for instance, to design a non-uniform surface texture (e.g., of light extraction features) for a lightguide, wherein the surface texture achieves a desired uniform or an intentionally non-uniform luminance distribution for a given lightguide shape/geometry, dimensions, and/or composition. In some embodiments, an iteration algorithm with illuminance distribution feedback is utilized to design a non-uniform surface texture (e.g., geometry, dimensions, quantity and/or spatial distribution of light extraction features) to achieve the target luminance distribution for a given lighting application.
摘要:
A system and method including self oscillating feedback for acoustic operation of a discharge lamp. The system includes a ballast configured to receive a modulation input and modulate a lamp power signal in accordance with the modulation input. A photodetector senses the optical output of the lamp to provide an electrical feedback to a feedback circuit. The feedback circuit filters the feedback to couple a portion thereof corresponding to a selected acoustic resonance mode of the lamp to the ballast as the modulation input thereby causing self-oscillation at the selected acoustic resonance mode.
摘要:
A method of detecting a leak in an outer jacket of a metal halide lamp having an arc tube inside the outer jacket and operated by a ballast, where the ballast monitors an electrical characteristic of the lamp during start and detects a leak in the outer jacket when the electrical characteristic deviates from that of a corresponding metal halide lamp whose outer jacket does not have a leak. The electrical characteristic is one of six markers, namely (1) V′(E) at a predetermined E, where V′(E) is a derivative of lamp voltage V as a function of cumulative energy E delivered to the ballast since ignition, (2) a value of E at which V′(E) reaches a maximum, (3) V at a predetermined E, (4) a local maximum of V′(E) up to a predetermined E, (5) a global maximum of V′(E), and (6) E required to achieve a predetermined V.
摘要:
A system and method for the operation of a mercury free high intensity discharge lamp is disclosed which provides lamp longevity and improved photometric results regardless of the orientation of the lamp. To this end, an acoustically modulated ballast without off-time and low power time is supplied to the lamp.
摘要:
Lighting systems and associated controls that can provide active control of lighting device settings, such as on/off, color, intensity, focal length, beam location, beam size and beam shape. In some examples, lighting systems may include eye tracking technology and sensor feedback for one or more lighting device settings and may be configured with depth perception and cavity or incision recognition capability through image or video processing.
摘要:
Lighting systems and associated controls that can provide active control of lighting device settings, such as on/off, color, intensity, focal length, beam location, beam size and beam shape. In some examples, lighting systems may include eye tracking technology and sensor feedback for one or more lighting device settings and may be configured with depth perception and cavity or incision recognition capability through image or video processing.
摘要:
Metal halide lighting with good color during dimming may be obtained. An appropriate balance of commonly used metal halides (NaI, DyI3, CeI3, CaI2, TlI) is dosed in the lamp. No mercury is used. A higher than typical xenon fill pressure from 50 to 500 Kilopascals may be used to help control thermal properties and voltage. If necessary, modulation of the power at acoustic resonance frequencies may be used to straighten and center the arc. Efficient and pleasant white output is obtained. As the power is reduced, the chromaticity either (1) remains fairly constant or (2) drifts acceptably towards warm pinkish colors. Large factors of attenuation in output can be realized. The lumen output was reduced by at least a factor of twenty in one sample as the power was dimmed from 70 to 20 watts.
摘要:
A method of controlling run-up of a metal halide lamp that has a nominal (full) light output during steady state operation and that has a current limit Ilim, includes, during run-up of the metal halide lamp to steady state operation, evaluating requested power Preq and requested current Ireq to operate the lamp at the nominal light output Ln during the run-up, supplying Ilim to operate the lamp so long as Ireq≧Ilim and supplying Preq to operate the lamp when Ireq
摘要:
A method of detecting a leak in an outer jacket of a metal halide lamp having an arc tube inside the outer jacket and operated by a ballast, where the ballast monitors an electrical characteristic of the lamp during start and detects a leak in the outer jacket when the electrical characteristic deviates from that of a corresponding metal halide lamp whose outer jacket does not have a leak. The electrical characteristic is one of six markers, namely (1) V′(E) at a predetermined E, where V′(E) is a derivative of lamp voltage V as a function of cumulative energy E delivered to the ballast since ignition, (2) a value of E at which V′(E) reaches a maximum, (3) V at a predetermined E, (4) a local maximum of V′(E) up to a predetermined E, (5) a global maximum of V′(E), and (6) E required to achieve a predetermined V.
摘要:
A method of controlling run-up of a metal halide lamp that has a nominal (full) light output during steady state operation and that has a current limit Ilim, includes, during run-up of the metal halide lamp to steady state operation, evaluating requested power Preq and requested current Ireq to operate the lamp at the nominal light output Ln during the run-up, supplying Ilim to operate the lamp so long as Ireq≧Ilim and supplying Preq to operate the lamp when Ireq