Apparatus and method of energy efficient illumination
AssigneeExpress Imaging Systems, LLC
InventorWilliam G. Reed
Life of this patent
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Abstract
An illumination system reduces a level of light output, and hence power consumption, at a time after turning ON a light source, and increases the level of light output at a time prior to turning OFF the light source. A control subsystem can determine when to increase the level of light based on a predicted time when the light source will be turned OFF. The control subsystem may determine an average or median length of time that the light source has been turned on for a number of recent daily cycles. A control subsystem may be an integral part of a luminaire or may be a retrofit.
Claims26
A method of operating an outdoor illumination system including at least one sensor and at least one control subsystem separately replaceable from the at least one sensor, the method comprising:
- processing by the at least one separately replaceable control subsystem information indicative of a level of illumination sensed by the at least one sensor over a plurality of daily cycles;
- the processing by the at least one separately replaceable control subsystem including:
- causing at least one illumination source to be turned ON at a first illumination level during a current one of the daily cycles;
- causing the at least one illumination source to be turned OFF during the current one of the daily cycles;
- causing a level of illumination produced by the at least one illumination source to be reduced from the first level to a non-zero level between the at least one illumination source being turned ON and OFF during the current one of the daily cycles;
- determining when to cause the level of illumination produced by the at least one illumination source to be increased, the increase to occur between the causing the level of illumination produced by the at least one illumination source to be reduced from the first level and the at least one illumination source being turned OFF, the determining based at least in part on the sensed level of illumination sensed during at least one previous one of the daily cycles which occurred before the current one of the daily cycles;
- and
- causing the level of illumination produced by the at least one illumination source to be increased between the causing the level of illumination produced by the at least one illumination source to be reduced and the at least one illumination source being turned OFF during the current one of the daily cycles.
A system for outdoor illumination, comprising:
- a housing including at least one base for receipt by an existing fixture illumination source receptacle and at least one receptacle for receiving an illumination source base;
- and
- a control subsystem that includes at least one control circuit, the control subsystem communicatively coupled to receive signals from at least one sensor, the control subsystem separately replaceable from the at least one sensor, the received signals indicative of a level of illumination over a plurality of daily cycles and that:
- causes at least one illumination source to be turned ON at a first illumination level during a current one of the daily cycles;
- causes at least one illumination source to be turned OFF during the current one of the daily cycles;
- causes a level of illumination produced by the at least one illumination source to be reduced from the first level to a non-zero level between the at least one illumination source being turned ON and OFF during the current one of the daily cycles;
- determines when to cause the level of illumination produced by the at least one illumination source to be increased, the increase to occur between the causing the level of illumination produced by the at least one illumination source to be reduced from the first level and the at least one illumination source being turned OFF, the determining based at least in part on the sensed level of illumination sensed during at least one previous one of the daily cycles which occurred before the current one of the daily cycles;
- and
- causes the level of illumination produced by the at least one illumination source to be increased between the causing the level of illumination produced by the at least one illumination source to be reduced and the at least one illumination source being turned OFF during the current one of the daily cycles.
Dependencies are inferred from the claim text.