초록 ▼

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

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.

대표청구항 ▼

1. A portable video camera and illumination source system, comprising:a housing; one or more light-emitting diodes (LEDs) attached to the housing; a video camera imaging device attached to the housing; a control circuit that selectively applies a plurality of pulses from a source of electric power t

1. A portable video camera and illumination source system, comprising:a housing; one or more light-emitting diodes (LEDs) attached to the housing; a video camera imaging device attached to the housing; a control circuit that selectively applies a plurality of pulses from a source of electric power to the one or more LEDs; and a feedback signal coupled to the control circuit, wherein the control circuit changes a characteristic of each one of the plurality of pulses to control a light output characteristic of the LEDs based on the feedback signal.