Abstract: The present invention provides an electronic circuit for driving a fluorescent lamp from a periodic input voltage provided at a power input terminal. The circuit comprises an inverter for powering the fluorescent lamp, and a control unit. The control unit comprises a measuring input connected to the power input terminal for providing a synchronization signal representing a value of the periodic input voltage to the control unit, a control input for receiving an input signal representative of a desired lighting characteristic of the fluorescent lamp, and a control output connected to an enabling input of the inverter. The control unit is arranged to provide, via the control output, a control signal to the inverter to operate the inverter in synchronism with a periodicity of the synchronization signal representing the value of the periodic input voltage, the control signal being based on the input signal.

Abstract: A driver (100; 200) for driving a dimmable load (L) is powered from phase-cut mains (U1) and determines the dimming state of the load on the basis of the phase of the cutting of the mains. The driver comprises: a load current generating device (130; 230) generating load current; a controllable auxiliary load (170; 270) connected to an input (131; 231) of the load current generating device; a control device (140; 240) controlling the auxiliary load. The control device has an input (141; 241) receiving a signal indicating the momentary voltage at the driver input. The load current generating device generates interrupted current pulses, so that the average output current corresponds to the dim command reflected by the phase cutting angle of the input mains. The control device switches the auxiliary load on during those time periods when the output current generated by the load current generating device is zero.

Abstract: A driver (100; 200) for driving a dimmable load (L) is powered from phase-cut mains (U1) and determines the dimming state of the load on the basis of the phase of the cutting of the mains. The driver comprises: a load current generating device (130; 230) generating load current; a controllable auxiliary load (170; 270) connected to an input (131; 231) of the load current generating device; a control device (140; 240) controlling the auxiliary load. The control device has an input (141; 241) receiving a signal indicating the momentary voltage at the driver input. The load current generating device generates interrupted current pulses, so that the average output current corresponds to the dim command reflected by the phase cutting angle of the input mains. The control device switches the auxiliary load on during those time periods when the output current generated by the load current generating device is zero.

Abstract: The present invention provides an electronic circuit for driving a fluorescent lamp from a periodic input voltage provided at a power input terminal. The circuit comprises an inverter for powering the fluorescent lamp, and a control unit. The control unit comprises a measuring input connected to the power input terminal for providing a synchronisation signal representing a value of the periodic input voltage to the control unit, a control input for receiving an input signal representative of a desired lighting characteristic of the fluorescent lamp, and a control output connected to an enabling input of the inverter. The control unit is arranged to provide, via the control output, a control signal to the inverter to operate the inverter in synchronism with a periodicity of the synchronisation signal representing the value of the periodic input voltage, the control signal being based on the input signal.

Abstract: Backlight unit comprising a supply source (4), a discharge lamp (2) having a tubular discharge vessel (6) with an ionizable filling, three or more electrodes (8, 10, 12) arranged in a row along and external of the vessel at spaced relation to each other. The supply source comprises lamp drivers (14, 16) and data processing means (18). Each pair of different pairs of electrodes is coupled to a corresponding lamp driver. Each lamp driver is suitable to supply a high frequency supply voltage to the pair of electrodes to which the lamp driver is coupled. The data processing means is suitable to process input display data (D) and to control the lamp drivers such that their supplied supply voltages are dependent on the input display data.

Abstract: To decrease a power consumption of a fluorescent lamp, the fluorescent lamp is provided with a high efficiency fluorescent coating, generating more light upon receipt of a conventional amount of radiation. Decreasing the power supplied to the lamp decreases the radiation supplied to the fluorescent coating and thus the light output of the lamp. Due to the increased light output of the fluorescent coating, the light output level of the fluorescent lamp may be kept substantially equal to a light output level of a conventional lamp.

Abstract: It is presented a lighting device comprising: at least one alternating current source configured to provide alternating current of at least a first and a second frequency, at least one light source, at least one impedance unit connected to the light source, affecting a first current from the at least one alternating current source to flow through the at least one light source, wherein an impedance of the impedance unit is configured to be frequency controlled, such that when the alternating current is of the first frequency the first current is relatively high and when the alternating current is of the second frequency the first current is relatively low. A corresponding display device, television device and method are also presented.

Abstract: The present invention relates to a backlight for a display device comprising at least a first light source arrangement (1) and a second light source arrangement (2) and drivers for controlling said light source arrangements. The backlight further comprises a third light source arrangement (3), wherein each one of the first and second light source arrangements (1, 2) is controlled by a respective driver (5, 6) such that luminance of the first and second light source arrangements (1, 2) are individually controllable, wherein each of the first and second light source arrangements (1, 2) is controlled such that luminance profile of the first and second arrangements (1, 2) is arranged to approximate at least a portion of a luminance profile of the third light source arrangement (3).

Abstract: Backlight unit comprising a supply source (4), a discharge lamp (2) having a tubular discharge vessel (6) with an ionizable filling, three or more electrodes (8, 10, 12) arranged in a row along and external of the vessel at spaced relation to each other. The supply source comprises lamp drivers (14, 16) and data processing means (18). Each pair of different pairs of electrodes is coupled to a corresponding lamp driver. Each lamp driver is suitable to supply a high frequency supply voltage to the pair of electrodes to which the lamp driver is coupled. The data processing means is suitable to process input display data (D) and to control the lamp drivers such that their supplied supply voltages are dependent on the input display data.

Abstract: A method of manufacturing an electron gun (10) for use in a color display tube (1) is described. The electron gun (10) is provided with an additional electrode (44), positioned between the anode electrode (21a) and the centering cup (23). This additional electrode (44) is part of the beaded unit (29) of the electron gun (10), and this enables very accurate positioning of this additional electrode (44) with regard to its distance to the main focusing section (21) as well as its rotation. This makes it possible to use this additional electrode (44) to improve the quality of the main focusing section (21) by considering it as an integral part of the main focusing section (21). For this reason this additional electrode is referred to as Main lens Field Modifier (MFM) (44).

Abstract: A method of manufacturing an electron gun (10) for use in a color display tube (1) is described. The electron gun (10) is provided with an additional electrode (44), positioned between the anode electrode (21a) and the centering cup (23). This additional electrode (44) is part of the beaded unit (29) of the electron gun (10), and this enables very accurate positioning of this additional electrode (44) with regard to its distance to the main focusing section (21) as well as its rotation. This makes it possible to use this additional electrode (44) to improve the quality of the main focusing section (21) by considering it as an integral part of the main focusing section (21). For this reason this additional electrode is referred to as Main lens Field Modifier (MFM) (44).