Led rescue light

Abstract

The present invention describes a rescue light with a LED light source that meets a minimum requirement of 0.75 candela (cd) of intensity, over a full hemisphere of visibility, with a duration of 8 hours or more. The invention requires only 3 volts of battery power from relatively small batteries, making the invention small and lightweight. In one favorite embodiment the LED is a specially constructed device that uses a blue LED die enclosed with a uniform layer of phosphor on the outer surface of the LED body, which provides an equally bright white light in all directions. Due to the low power requirements of the LED, the device can easily produce white light over an entire hemisphere at the required brightness level for longer than the required amount of time. In another favorite embodiment, a power LED with a large viewing angle is powered with a relatively high current, so as to meet the requirements for intensity over the entire hemisphere, but the high current is applied for only short periods of time in order to meet the requirement for duration. In this second embodiment, a novel switching arrangement is provided to allow the user to turn the LED on and off by changing positions of a movable member of the device, where the original position of the movable member is independent of the operational state of the device. In a third favorite embodiment, multiple LEDs are incorporated for greater visibility, and the operational state of the device is changed by pressing a momentary switch. In all of the described embodiments, a water sensitive switch may be provided to activate the LED on contact with a body of water.

Dependencies are inferred from the claim text.