Abstract: Methods and apparatus are provided for improving the efficiency of a fluorescent lamp suitable for use as a backlight in an avionics or other liquid crystal display (LCD). The apparatus includes a channel configured confine a vaporous material that produces an ultra-violet light when electrically excited. A first electrode and a second electrode assembly disposed within the channel and configured to apply an electrical potential across at least a portion of the channel to electrically excite the vaporous material. Control circuitry is configured to provide control signals to the first and second electrodes to apply the electrical potential in a manner that produces a mean electron energy that substantially maximizes probabilities of collisions between electrons and particles that that produce more emissions in the light-producing channel having wavelengths substantially less than 400 nm than emissions having wavelengths greater than 800 nm.

Abstract: Methods and apparatus are provided for increasing the life of a fluorescent lamp suitable for use as a backlight in an avionics or other liquid crystal display (LCD). The apparatus includes a channel configured confine a vaporous material that produces an ultra-violet light when electrically excited. A layer of light-emitting material disposed within at least a portion of the channel is responsive to the ultra-violet light to produce the visible light emitted from the lamp. To increase the lifespan of the lamp, a protective coating is provided on the layer of light-emitting material. The protective coating comprises a material that is transparent to both ultra-violet and visible light, yet is capable of filling even small gaps in the light-emitting material. In lamps wherein the vaporous material comprises mercury and the light-emitting material comprises a phosphorescent material, for example, the protective material may comprise fused silica (i.e. silica dioxide or “quartz glass”).

Abstract: Methods and apparatus are provided for increasing the life of a fluorescent lamp suitable for use as a backlight in an avionics or other liquid crystal display (LCD). The apparatus includes a channel configured confine a vaporous material that produces an ultra-violet light when electrically excited. A layer of light-emitting material is disposed within at least a portion of the channel is responsive to the ultra-violet light to produce the visible light emitted from the lamp. An electrode assembly that electrically excites the vaporous material includes a first post, a second post, a conductive filament suspended between the first post and the second post and having a tail portion extending therebeyond, and a benign insulating material such as glass frit substantially covering the tail portion to prevent radio frequency (RF) emissions from the tail portion of the filament.

Abstract: Methods and apparatus are provided for increasing the luminous output of a fluorescent lamp suitable for use as a backlight in an avionics or other liquid crystal display (LCD). The apparatus includes a channel configured confine a vaporous material that produces an ultra-violet light when electrically excited. A layer of light-emitting material disposed within at least a portion of the channel is responsive to the ultra-violet light to produce the visible light emitted from the lamp. To increase the luminous output of the lamp, the surface area of the light-emitting material is increased through the presence of one or more grooves. The grooves may be longitudinal or transverse with respect to the channel.

Abstract: Methods and apparatus are provided for identifying the presence of leaks in a fluorescent bulb or other lamp suitable for use as a backlight in an avionics or other liquid crystal display (LCD). The lamp is first placed in a bath of helium or another vaporous substance having relatively small molecular size. The vaporous material is allowed to permeate through any leaks that may exist in the lamp and to thereby intermix with the light-producing vaporous material contained within the channel of the lamp. The lamp is removed from the bath and subsequently operated (e.g. at a low intensity), and the output electrical or optical characteristics of the lamp under test are obtained. If the output characteristics of the lamp under test substantially correspond to characteristics obtained from a lamp that is known to be in proper working order, then the absence of leaks in the lamp under test can be presumed.

Abstract: Methods and apparatus are provided for increasing the efficiency of a fluorescent lamp suitable for use as a backlight in a liquid crystal display (LCD). The apparatus includes a light producing cavity/channel that encloses a vaporous material that produces an ultraviolet light when electrically excited. A layer of light-emitting material within the channel produces the visible light emitted from the lamp in response to the ultraviolet light, and a faceplate made up of a substantially transparent material is affixed to the cavity to confine the vaporous material. To increase the efficiency of the lamp, a coating is provided on the faceplate that reflects ultraviolet light and transmits visible light. The coating may be applied on either the internal or external surface of the faceplate.

Abstract: Methods and apparatus are provided for identifying the presence of leaks in a fluorescent bulb or other lamp suitable for use as a backlight in an avionics or other liquid crystal display (LCD). The lamp is first placed in a bath of helium or another vaporous substance having relatively small molecular size. The vaporous material is allowed to permeate through any leaks that may exist in the lamp and to thereby intermix with the light-producing vaporous material contained within the channel of the lamp. The lamp is removed from the bath and subsequently operated (e.g. at a low intensity), and the output electrical or optical characteristics of the lamp under test are obtained. If the output characteristics of the lamp under test substantially correspond to characteristics obtained from a lamp that is known to be in proper working order, then the absence of leaks in the lamp under test can be presumed.

Abstract: A driver circuit provides electrical energy from a power source to a fluorescent lamp such as that used in a flat-panel or other liquid crystal display (LCD). The circuit includes a transformer having a primary winding and a secondary winding, with the ends of the secondary winding coupled to the fluorescent lamp. A first switch switchably provides a drive output signal to the transformer based upon a switch input signal. A current control loop adjusts the switch input in response to the current in one of the windings of the transformer, and a luminance control loop adjusts the switch input in response to the brightness of the light. A lamp current frequency control loop adjusts the polarity of the primary winding in response to a signal received from the transformer to thereby adjust the frequency of the lamp drive current applied to the fluorescent lamp.

Abstract: A lamp driver system is provided that facilitates improved efficiency and brightness control for an optical display system. The lamp driver system provides this improved efficiency and brightness control through the precise control of the plasma in the lamp. The lamp driver system excites the electrons in the plasma such that their obtained velocity is optimized to increase the probability of collision with the mercury atoms in the lamp. Collisions with mercury atoms release ultra-violet photons, which in turn excites the phosphor coating in the lamp. The resulting relaxation of the phosphor atoms releases photons in the visible spectrum, thus providing light with the required frequency components to illuminate the display.