Abstract: A tab is cut into a sheet of transparent material. The tab has a free end and a fixed end. A source of light is attached to the tab and the tab and the sheet are displaced along the z-axis of the sheet to direct light from the source into an edge of the sheet. The tab can include conductive traces for electrical connection to the light source or other electrical devices on the sheet. A variable display device adjacent the sheet is viewed through the sheet and the sheet with attached light source provides front lighting for the variable display device.

Abstract: A tab is cut into a sheet of transparent material. The tab has a free end and a fixed end. A source of light is attached to the tab and the tab and the sheet are displaced along the z-axis of the sheet to direct light from the source into an edge of the sheet. The tab can include conductive traces for electrical connection to the light source or other electrical devices on the sheet. A variable display device adjacent the sheet is viewed through the sheet and the sheet with attached light source provides front lighting for the variable display device.

Abstract: A portable computer comprises a housing and an EL panel within the housing, positioned to emit light outwardly from the housing. The EL panel includes a plurality of EL lamps that, together, form a logo. The EL lamps can be addressed separately, enabling one to produce the appearance of motion for decorative effect or to indicate a condition of the portable computer or both.

Abstract: A light shutter and an EL panel are sandwiched between two substrates, one of which includes a common front electrode. The common front electrode is electrically floating. Patterned rear electrodes, on either side of the EL panel, are capacitively coupled to each other by the common front electrode. The rear electrodes can be segmented and the segments addressed individually. Each substrate is coated with a layer of PDLC and the substrates are laminated by joining the layers of PDLC.

Abstract: A layer having a refractive index less than that of a light guide can be used as a refractive layer, rather than a reflective layer, for increasing light output. The effect is improved if the refractive layer is patterned to correspond to light extracting features on the surface of the light guide. The refractive layer and the light extracting features are on opposed surfaces of the light guide. The refracting layer can be deposited from ink at relatively low cost.

Abstract: An inverter is coupled to an EL lamp by a high pass filter including a series capacitor and a shunt resistor. The resistor is coupled in parallel with the EL lamp. The high pass filter has a time constant greater than 0.005 seconds and the capacitor has a capacitance at least ten times the capacitance of the EL lamp.

Abstract: An inverter is coupled to an EL lamp by a high pass filter including a series capacitor and a shunt resistor. The resistor is coupled in parallel with the EL lamp. The high pass filter has a time constant greater than 0.005 seconds and the capacitor has a capacitance at least ten times the capacitance of the EL lamp.

Abstract: A light source and a liquid crystal display are separated by a transparent, color graphic to simulate a color liquid crystal display. The light source preferably produces a substantially white light, as is available by cascading materials, and includes discrete or diffuse sources. The liquid crystal display is preferably positive (black on white) rather than negative to reveal more of the graphic. With an EL light source, the graphic can be printed on the transparent substrate of the EL lamp. In liquid crystal displays having a transflective layer, the transflective layer can be located between the light source and the graphic layer.