A light source particularly adapted to provide emergency lighting and having an extremely long standby life is disclosed. The light source comprises a compartmentalized plastic tube having a light bulb in one compartment, a pair of electrodes in another compartment and an electrolyte in a third compartment. The electrolyte compartment houses an electrolyte which is stored in a frangible envelope. The plastic material which forms the first two compartments is stiff or rigid; while the plastic material surrounding the electrolyte compartment is flexible. To actuate the light source one squeezes or otherwise puts pressure on the flexible portion of the plastic tube to fracture the frangible envelope, thereby permitting the electrolyte to flow from its container and saturate the electrodes. The light bulb compartment is isolated from the electrode compartment to prevent the flow of electrolyte into the light bulb compartment. Further, the light bulb compartment may be detachable. In order to prevent accidental fracture of the electrolyte envelope, the flexible portion of the plastic tube may be covered by a removable thin metallic or plastic shroud.
A disposable flashlight uniquely suited to operation in high humidity and water exposure conditions, such as those encountered in search and rescue missions at sea. The bulb, which is preferably a high intensity super-bright light emitting diode, is energized to produce light using a battery connected to it via a switch and an electrical circuit. The switch completes the electrical circuit via an electrically conducting fluid, allowing the electrical current to flow from the battery and the bulb to illuminate.
The disclosed device provides illumination for a radiation dosimeter or other tubular instrument which is held directly in front of the eye for viewing. It can also be used as a compact flashlight for inconspicuous use such as for reading a map in a car or a program in a theater, and it can be carried by medical personnel to illuminate the eye of a patient. The illuminator comprises a light-emitting diode (LED) protruding through an annular spacer. The leads from the LED are bent around a battery comprising one or more button cells. The inner assembly comprising the LED, spacer and battery is held together by a plastic sleeve of shrink-wrap material, such as polyolefin. The inner assembly is enclosed in a thimble-shaped flexible plastic casing, which is adapted to slide onto the end of a dosimeter for permanent mounting. When the user squeezes the casing, the leads are brought into contact with the batteries, thereby completing the circuit, lighting the LED, and illuminating the dosimeter. The illuminator is fabricated by assembling the parts within a heat-shrinkable plastic sleeve, heating the sleeve to shrink it around the parts to secure them together, and then inserting the shrink-wrapped assembly within the casing.
