Method and apparatus for an L.E.D. flashlight
DCFirst Claim
1. A flashlight, comprising:
- (a) a flashlight housing, the housing being suitable for at least one of receiving therein and mounting thereon at least one DC voltage source;
(b) a light-emitting diode (LED) housing connected to the flashlight housing, the LED housing comprising a first plurality of LED units that each emit light and have a reflector for collimating the emitted light forwardly therefrom generally along an optical axis of one of the plurality of LED units, the first plurality of LED units including at least seven individual LED units; and
(c) a first electrical circuit that selectively applies pulsed power from the DC voltage source to the LED units, wherein the pulses have a frequency high enough that light produced by the LED units has an appearance to a human user of being continuous rather than pulsed, and the pulses have at least one characteristic that is controlled by the first electrical circuit in order to maintain an average predetermined light output level of the LED units as a voltage on the DC voltage source varies;
wherein the flashlight is of such compact size and low weight as to be suitable for single-handed portable operation by a user, the flashlight further having a purpose of providing general-purpose illumination.
6 Assignments
Litigations
4 Petitions
Accused Products
Abstract
Improved method and apparatus for hand-held portable illumination. A flashlight and corresponding method are described. The flashlight includes a housing, a plurality of LEDs, and an electrical circuit that selectively applies power from the DC voltage source to the LED units, wherein the flashlight is suitable for handheld portable operation by a user. In one embodiment, the first electrical circuit further includes a control circuit for maintaining a predetermined light output level of the LED units as a charge on a battery varies. In another embodiment, the control circuit maintains an average predetermined light output level of the LED units as the charge on the battery cell varies by changing a pulse width or frequency as the charge on the battery cell varies to maintain a given average light output. Another aspect provides an illumination source that includes a light-emitting diode (LED) housing including one or more LEDs, and a control circuit that selectively applies power from a source of electric power to the LEDs, the control circuit substantially maintaining a light output characteristic of the LEDs as a voltage of the voltage source varies over a range that would otherwise vary the light output characteristic. Still another aspect provides an illumination source including a light-emitting diode (LED) housing including one or more LEDs; and a control circuit that selectively applies power from a source of electric power to the LEDs, thus maintaining or controlling a light output color spectrum of the LEDs.
699 Citations
52 Claims
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1. A flashlight, comprising:
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(a) a flashlight housing, the housing being suitable for at least one of receiving therein and mounting thereon at least one DC voltage source; (b) a light-emitting diode (LED) housing connected to the flashlight housing, the LED housing comprising a first plurality of LED units that each emit light and have a reflector for collimating the emitted light forwardly therefrom generally along an optical axis of one of the plurality of LED units, the first plurality of LED units including at least seven individual LED units; and (c) a first electrical circuit that selectively applies pulsed power from the DC voltage source to the LED units, wherein the pulses have a frequency high enough that light produced by the LED units has an appearance to a human user of being continuous rather than pulsed, and the pulses have at least one characteristic that is controlled by the first electrical circuit in order to maintain an average predetermined light output level of the LED units as a voltage on the DC voltage source varies; wherein the flashlight is of such compact size and low weight as to be suitable for single-handed portable operation by a user, the flashlight further having a purpose of providing general-purpose illumination. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49)
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12. A flashlight, comprising:
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(a) a flashlight housing, the housing being suitable for at least one of receiving therein and mounting thereon at least one DC voltage source that includes at least one battery cell; (b) a light-emitting diode (LED) housing connected to the flashlight housing, the LED housing comprising one or more first LED units that each emit light and have a reflector for collimating the emitted light forwardly therefrom generally along an LED optical axis; and (c) a first electrical circuit that selectively applies power from the DC voltage source to the LED units, the first electrical circuit further comprising a control circuit for maintaining a predetermined light output level of the LED units as a charge on the battery cell varies; wherein the flashlight is of such compact size and low weight as to be suitable for single-handed portable operation by a user, the flashlight further having a purpose of providing general-purpose illumination. - View Dependent Claims (13, 14, 15, 16, 50)
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17. A method of providing general-purpose illumination of such compact size and low weight as to be suitable for single-handed portable operation by a user, comprising the steps of:
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(a) providing one or more first LED units that each emit light and have a reflector for collimating the emitted light forwardly therefrom generally along an LED optical axis; (b) selectively applying power from a DC voltage source to the LED units; and (c) maintaining a predetermined light output level of the LED units as a charge on the DC voltage source varies by controlling the step (b). - View Dependent Claims (18, 19, 20)
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21. An illumination source, comprising:
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(a) a light-emitting diode (LED) housing comprising one or more LEDs; and (b) a control circuit that selectively applies power from a source of electric power to the LEDs, the control circuit substantially maintaining a light output characteristic of the LEDs as a voltage of the voltage source varies over a range that would otherwise vary the light output characteristic. - View Dependent Claims (22, 23, 24, 25)
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26. A battery-powered portable flashlight (100) comprising:
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a casing (110) suitable to hold a battery; one or more light-emitting devices (LEDs) (150) mounted to the casing; a switch (140) mounted to the casing; and a control circuit (130) coupled to the battery, the LEDs, and the switch, wherein the control circuit drives the LEDs with electrical pulses at a frequency high enough that light produced by the LEDs has an appearance to a human user of being continuous rather than pulsed, and wherein the LEDs have proportion of on-time that increases as remaining battery power decreases. - View Dependent Claims (27, 28, 29, 38)
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30. A method for driving battery-powered portable flashlight (100) having a casing (110), a DC power source mounted to the casing, one or more solid-state light-emitting device (LEDs) (150) mounted to the casing, the method comprising the steps of:
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receiving input from a user; and based on the received input, generating a series of pulses to drive the LEDs such that the LEDs have proportion of on-time that increases as remaining battery power decreases.
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31. An illumination source, comprising:
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(a) a light-emitting diode (LED) housing comprising one or more LEDs; (b) a source of electrical power; and (c) a control circuit that selectively applies power from a source of electric power to the one or more LEDs to substantially maintain a predetermined color spectrum of the one or more LEDs as a voltage of the source of electric power varies over a range that would otherwise vary the light output color spectrum. - View Dependent Claims (32, 33)
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34. An illumination source, comprising:
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(a) a light-emitting diode (LED) housing comprising one or more LEDs; and (b) an electrical control circuit that selectively applies pulsed power from a DC voltage source of electric power to the LEDs to control a light output color spectrum of the one or more LEDs and maintain a predetermined light output level of the LED units as a charge on the DC voltage source varies. - View Dependent Claims (35, 36, 37, 51, 52)
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Specification