Method and apparatus for constant light output pulsed L.E.D. illumination
DCFirst Claim
1. A method of providing general-purpose illumination in a device of such compact size and low weight as to be suitable for single-handed portable operation by a user, comprising:
- providing at least one LED in a housing configured to be held in a single hand, wherein each of the at least one LED emits light when driven by an electrical current;
connecting a battery to the housing;
electronically switching to alternately connect and disconnect an electrical path between the battery and the at least one LED at a high-enough frequency such that a human eye would not perceive the switching; and
controlling, across a battery-voltage range that would otherwise vary an average intensity of LED light output, the electronic switching to generate a substantially constant average light output intensity from the at least one LED.
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Abstract
An illumination source includes a plurality of LEDs, and an electrical circuit that selectively applies power from the DC voltage source to the LED units, wherein the illumination source is suitable for handheld portable operation. In some embodiments, the electrical circuit further includes a control circuit for driving the LEDs with electrical pulses at a frequency high enough that light produced has an appearance to a human user of being continuous rather than pulsed, the control circuit changing a pulse characteristic to adjust a proportion of light output having the first characteristic color spectrum output to that having the second characteristic color spectrum output. Some embodiments provide an illumination source including a housing including one or more LEDs; and a control circuit that selectively applies power from a source of electric power to the LEDs, thus controlling a light output color spectrum of the LEDs.
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Citations
20 Claims
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1. A method of providing general-purpose illumination in a device of such compact size and low weight as to be suitable for single-handed portable operation by a user, comprising:
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providing at least one LED in a housing configured to be held in a single hand, wherein each of the at least one LED emits light when driven by an electrical current; connecting a battery to the housing; electronically switching to alternately connect and disconnect an electrical path between the battery and the at least one LED at a high-enough frequency such that a human eye would not perceive the switching; and controlling, across a battery-voltage range that would otherwise vary an average intensity of LED light output, the electronic switching to generate a substantially constant average light output intensity from the at least one LED. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An LED illumination source apparatus, comprising:
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a housing of such compact size and low weight as to be suitable for single-handed portable operation by a user, and configured to hold a battery; at least one LED mounted to the housing; and a control circuit having an electronic switch operatively coupled to alternately connect and disconnect electrical power from the battery to the control circuit, such that the control circuit selectively applies electrical power from the battery to the at least one LED, wherein the control circuit maintains a substantially constant average light output characteristic of the at least one LED as a voltage of the voltage source varies over a range that would otherwise vary the light output characteristic by adjusting a proportion of connect time to disconnect time. - View Dependent Claims (12, 13, 14, 15)
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16. An apparatus for providing general-purpose illumination of such compact size and low weight as to be suitable for single-handed portable operation by a user, comprising:
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a housing configured to be held in a single hand; an LED that emits light when driven by an electrical current, wherein the LED is mounted to the housing; means for mounting a battery to the housing; means for electronically switching to alternately connect and disconnect an electrical path between the battery and the at least one LED at a high-enough frequency such that a human eye would not perceive the switching; and means for controlling, across a battery-voltage range that would otherwise vary an average intensity of LED light output, the means for electronic switching to generate a substantially constant average light output intensity from the at least one LED. - View Dependent Claims (17, 18, 19, 20)
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Specification