Abstract: EL panels are made with PVDF/HFP copolymer resin binder, in substantially an un-crosslinked form, with DMAC solvent and/or other higher boiling point solvents/latent solvents/extenders. The resin binder is characterized by a melt viscosity of 1.0-8.5 kP using an industry standard test (ASTM D3835).

Abstract: An inverter for driving an EL lamp is tapped to provide voltage or current for driving one or more EL lamps, LEDs, and an LCD. In accordance with one aspect of the invention, one side of the pump inductor is tapped for a voltage that drives one or more LEDs and the LCD. In accordance with another aspect of the invention, the LEDs are in series with a storage capacitor and are driven by the current pulses to the storage capacitor.

Abstract: An electroluminescent lamp includes two electrodes and at least three connectors, a first connector coupled to a first electrode and a second connector and a third connector coupled to the second electrode. A first electric current flows through the lamp between the first connector and the second connector, causing the lamp to emit light. A second electric current flows through the second electrode between the second connector and the third connector, whereby the second electrode increases in temperature in response to the second electric current. When backlighting a liquid crystal display, the second electrode provides heat to warm the display for proper operation. Either electrode can be used as a heater.

Abstract: A light guide directs some light from an EL lamp into a display and absorbs or redirects the remaining light in a direction different from the preferred viewing angle for the display, thereby preserving the contrast of the display. The display includes a substantially transparent light guide having a first major surface and a second, opposed major surface and at least two opposed edges. An EL lamp is optically coupled to the light guide along a first of the opposed edges and the light guide includes grooves in one of the major surfaces for re-directing light from the EL lamp out of the one of the major surfaces.

Abstract: Lamp materials, e.g. a phosphor layer and a dielectric layer, are roll coated onto a release layer. A photodetector is coated with a translucent conductive layer and the lamp materials are laminated to the transparent conductive layer. The release layer is removed and a protective coating is applied to the dielectric layer. A resin coating is optionally applied to the transparent conductive layer prior to lamination to improve adhesion. The protective coating can be incorporated into the lamp materials prior to lamination. The release layer can be coated by screen printing or other deposition technique rather than by roll coating.

Abstract: A personal electronic device includes and inverter having a single inductor for powering an EL lamp and a buzzer. The lamp and the buzzer are coupled together to the output of the inverter and are in parallel with each other or are coupled in series between a source of direct current and ground.

Abstract: An inverter includes a fourth order impedance network coupled between the output and the input of an amplifier, causing the inverter to oscillate and produce a high voltage at an output of the impedance network. The impedance of one portion of the impedance network is preferably at least ten times the impedance of a second portion of the impedance network at the frequency of oscillation.

Abstract: A driver for an EL lamp includes a voltage detector coupled to the lamp for monitoring the voltage across the lamp and providing an indication of when the lamp is substantially discharged.

Abstract: A driver for an EL lamp includes a source of high voltage coupled to a first voltage rail and a second voltage rail and a transistor bridge output coupled to the rails, wherein the bridge output has no current mirrors for the high side transistors in the bridge output.

Abstract: An inverter for driving an EL lamp includes a half-bridge output. The inverter can be implemented in junction isolation processes, among others, on smaller die than in the prior art in a package with a lower pin count than known circuits of the same functionality.

Abstract: A power supply for an EL lamp includes a boost circuit and four semiconductor switches connected as a bridge having an AC diagonal and a DC diagonal having one end grounded. The voltage boost circuit is coupled across the DC diagonal and an electroluminescent lamp is coupled across the AC diagonal of the bridge. The two semiconductor switches coupled to ground are SCRs.

Abstract: An inverter for driving an EL lamp includes a half-bridge output. The inverter can be implemented in junction isolation processes, among others, on smaller die than in the prior art in a package with a lower pin count than known circuits of the same functionality.

Abstract: An EL lamp is powered by bursts of high frequency signal repeated at low frequency, i.e. having a low duty cycle envelope, in order to shift the color of light emitted by the phosphor in the lamp without degrading the life of the lamp. The bursts include one or more consecutive cycles of a high frequency signal or several closely spaced cycles of a high frequency signal.

Abstract: An inductive boost circuit is added in parallel with an inverter to increase current to an EL lamp. The inverter and the boost circuit each include a switching transistor. The switching transistor in the inductive boost circuit may be matched to the switching transistor in the inverter and may be driven synchronously with the switching transistor in the inverter.

Abstract: An electroluminescent lamp assembly includes electroluminescent lamps of selected limited size placed and secured upon a larger printed circuit substrate employing surface mount techniques. The electroluminescent lamp assembly includes a substrate having a relatively large lamp receiving surface and relatively smaller lamps. At least one of these smaller lamps is a multi-layer sheet-form electroluminescent lamp having a sheet-form layer containing electroluminescent particles, the layer disposed between a pair of sheet-form conductive layers, one of which is transparent for transmitting light emitted from the particles. The electroluminescent lamps each have conductors exposed for engagement and connection with conductive traces on the lamp receiving surface of the substrate in a surface mounted face-to-face arrangement and are distributed in spaced-apart relationship according to a preselected illumination pattern and connected to the conductive traces.

Abstract: An EL lamp is driven by a power supply including a voltage boost circuit and a low power inverter. The boost circuit includes a level shifting capacitor to provide voltage doubling. The inverter includes an inductor and at least one transistor connected in series between the output of the boost circuit and ground.

Abstract: An EL lamp includes hole for receiving fitting attached to a printed circuit board. The fitting has a base, a head, and a neck connecting the head to the base. The diameter of the head is slightly larger than the diameter of the hole and the head fits though the hole by temporarily stretching the lamp. The lamp includes a substrate, a front electrode, a phosphor layer, and a rear electrode. The rear electrode faces the base. Contact to the front electrode is made through a first aperture in the rear electrode and in the phosphor layer. A second aperture, through the front electrode and the phosphor layer, exposes a portion of the substrate that is covered by the rear electrode. The apertures are aligned with two of the holes in the lamp.

Abstract: In a process for making an EL lamp, a rear electrode is roll coated on a temporary substrate, followed by successive roll coatings of a dielectric layer and a phosphor layer. A transparent, conductive layer on a transparent substrate is laminated to the phosphor layer layer and the temporary substrate is removed. The layers are applied from a slurry or ink and bladed to a uniform thickness across the width of the temporary substrate. The process can be continuous using rolls of material for the temporary substrate. The length of a lamp is limited by the length of the temporary substrate. The width of the lamp is determined by the size of the apparatus used to apply and to spread the layers.

Abstract: An EL lamp has a perimeter that is beveled such that the rear electrode is smaller in area than the front electrode due to the bevel. The lamp is made by placing an EL panel on a concave die with the rear electrode in contact with the die and shearing the edge of the lamp at an acute angle between 30.degree. and 60.degree., preferably 45.degree.. For circular or nearly circular lamps, the entire perimeter of the lamp can be cut in a single stroke.

Abstract: At least one conductive layer runs the length of an EL panel and individual lamps are connected to the conductive layer. In one embodiment of the invention, the electroluminescent layer of the panel does not cover a portion of the front electrode and the conductive layer is electrically coupled to the exposed portion of the front electrode. In another embodiment of the invention, the EL panel includes at least two rear electrodes and the conductive layer is coupled to one of the rear electrodes. An insulating layer between the conductive layer and other parts of the EL panel prevents unintended electrical connections to the conductive layer.