Abstract: One or more systems and/or methods are disclosed for building a relief print generator with no bezel. An electrode layer having more than one electrode can be used in an electrode-based, electro-luminescence component of the relief print generator. The respective electrodes may be connected to power sources with different voltage phases. An electrical circuit can be created between a biometric object and more than one electrode in the electrode layer when the biometric object contacts a surface of the generator. The electro-luminescent component can be activated by electrical charge and emit light indicative of a relief print of the biometric object. A contact electrode outside the electrode layer may not be used, which may allow for the removal of a bezel from an example device.

Abstract: One or more systems and/or methods are disclosed for building a relief print generator with no bezel. An electrode layer having more than one electrode can be used in an electrode-based, electro-luminescence component of the relief print generator. The respective electrodes may be connected to power sources with different voltage phases. An electrical circuit can be created between a biometric object and more than one electrode in the electrode layer when the biometric object contacts a surface of the generator. The electro-luminescent component can be activated by electrical charge and emit light indicative of a relief print of the biometric object. A contact electrode outside the electrode layer may not be used, which may allow for the removal of a bezel from an example device.

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 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 EL lamp is driven by a flyback inverter having an inductor connected in series with a first transistor which switches on and off at a high frequency. The junction of the inductor and transistor is connected through a switching diode to an output terminal for connection to an EL lamp. A discharge path, including a second transistor, is coupled to the lamp for removing accumulated charge. The second transistor switches on and off at a low frequency for periodically discharging the electrical charge accumulated on the EL lamp. In accordance with one aspect of the invention, several diodes are connected in series with the switching diode to block waste current during discharge of the EL lamp. In accordance with another aspect of the invention, the switching diode is temporarily by-passed to provide the discharge path for the lamp. In accordance with either aspect of the invention, the inverter can produce alternating current through the lamp by adding a capacitor in series with the lamp.

Abstract: An EL lamp characterized by non-linear brightness decay is driven to constant brightness for the life of the lamp by an inverter controlled by a microprocessor. The microprocessor controls the inverter in accordance with a table containing data which is the inverse function of the non-linear brightness decay. The microprocessor tracks the total on-time of the EL lamp and selects the appropriate data from the table for driving the lamp. Control can be analog or digital. If control is analog, the selected data is coupled to a D/A converter which is coupled to the inverter. If control is digital, the selected data is coupled to a counter driving a pulse width modulator which is coupled to the inverter. In accordance with another aspect of the invention, an EL lamp is dimmed a precise amount based upon the data in the table and the EL lamp can be dimmed in unison with other lamp types, each lamp type having a table containing data for dimming.

Abstract: An electronic watch, either digital or analog, includes an EL lamp powered by a split chip inverter having a low voltage portion incorporated into a first semiconductor chip and a high voltage portion incorporated in a second semiconductor chip. The first semiconductor chip preferably includes all the other low voltage circuitry of the watch, e.g. timer/divider circuitry and logic for driving a display.

Abstract: A power supply for an electroluminescent lamp includes a pair of inverters for alternately powering the EL lamp from a low voltage DC source. A first inverter is connected to a first electrode of the EL lamp and a transistor is connected between the first electrode and electrical ground. A second inverter is connected to a second electrode of the EL lamp and a second transistor is connected between the second electrode and electrical ground. A pulse generator connected to the inverters and the transistors operates the inverters and transistors to power the EL lamp alternately from one inverter and then the other. In one embodiment of the invention, the voltage across the EL lamp is referenced to ground and, in another embodiment, the voltage across the EL lamp is referenced to the voltage of the DC source.

Abstract: DC bias does not accumulate on an EL lamp connected in series with a switch circuit including, in one embodiment, two, asymmetric, parallel current paths, one current path for each half cycle of the AC. The first current path includes a first diode for preventing DC bias on the lamp, the first diode is in series with a first transistor between a first terminal and a second terminal. The second current path includes a second diode in series with the base-collector junction of a second transistor between the first terminal and the second terminal. The base of the first transistor is connected to the emitter of the second transistor and to a control terminal. The first transistor and the second transistor are opposite conductivity types. The second current path takes advantage of the fact that the current through an electroluminescent lamp is small and uses the control terminal as a source of current for the lamp.

Abstract: An inverter for powering an electroluminescent lamp has a direct current supply terminal, a ground terminal, and a single output terminal. A high frequency pumping circuit stores electrical energy in an inductor having a first terminal and a second terminal. A switching circuit alternately connects the first and second terminals of the inductor to the output terminal at a low frequency. The output from the inverter is a high voltage, low frequency, alternating current.