Abstract: A field emission backlight module has a field emission structure with cathode and anode provided on the same plane, so that electrons directly penetrate an independently provided fluorescent powder layer to produce light. The light is emitted uniformly without the need of the conventional optical membrane. Since the light produced by the fluorescent powder layer is not blocked by the anode, the problem of charge accumulation on the fluorescent powder layer is avoided, and it is not necessary to use expensive light-transmittable conducting glass as the anode. With the cathode and the anode located at the same plane, it is not necessary to use a precision spacer to adjust the distance between the cathode and the anode, enabling the module to be manufactured at reduced cost and high good yield. When the color sequential displaying method is adopted, expensive color filters required in the conventional LCD may be omitted.

Abstract: A color converting molding material and a light emitting device having the color converting molding material are discussed.

Abstract: The invention relates to the improvement of phosphorescing organic electroluminescent devices characterized in that the emission layer, which consists of a matrix material which is doped with at least one phosphorescing emitter, directly adjoins an electrically conducting layer.

Abstract: An organic electro-luminescent device including a substrate, a plurality of organic electro-luminescent units and a reflective electrode layer is provided. The organic electro-luminescent units are stacked on the substrate, and the reflective electrode layer is disposed between the adjacent organic electro-luminescent units. As mentioned above, the organic electro-luminescent device can provide double-sided display function.

Abstract: An aromatic amine derivative with a special structure bonding to a fused polycyclic hydrocarbon group having silyl group. An organic electroluminescence device which comprises one or more organic thin film layers comprising at least a light emitting layer sandwiched between a cathode and an anode, wherein at least one of the organic thin film layer comprises the above aromatic amine derivative singly or as its mixture component. An organic electroluminescence device having a long lifetime and an enhanced efficiency of light emission together with the aromatic amine derivatives realizing the device are provided.

Abstract: A light emitting device includes: a plurality of transistors individually corresponding to a plurality of pixels arrayed in a matrix shape, and a plurality of wiring lines connected with the transistors and disposed between the pixels. The wiring lines include signal lines connected with the transistors of the pixel columns composed of a plurality of pixels along a row direction or a column direction, and two or more common electrode lines connected with the transistors of a pixel group composed of a plurality of pixels along the row direction and the column direction. The common electrode lines are arranged on the two sides centering the signal lines.

Abstract: An organic electroluminescence device including a pair of electrodes and at least one organic compound layer comprising a light-emitting layer between the pair of electrodes, wherein a refractive index of at least one of the light-emitting layer or an organic compound layer on the light extraction side of the light-emitting layer is 1.6 or less. An organic EL device in which luminescence can extracted with high efficiency and luminescence of high brightness can be obtained.

Abstract: An organic thin film transistor (TFT), a method of manufacturing the organic TFT, and a flat display apparatus having the organic TFT are provided. The organic TFT has a gate insulating layer with openings filled with a conductive material, thereby preventing short circuits from occurring between channels connecting the source and drain lines to the organic semiconductor layer. The organic TFT includes a substrate including a source line, a drain line, and a gate electrode. The organic TFT further includes a gate insulating layer formed on the source and drain lines and on the gate electrode. The gate insulating layer has openings exposing the source and drain lines, which openings are filled with a conductive material. The organic TFT also includes an organic semiconductor layer electrically connected to the conductive material.

Abstract: To provide a light emitting device high in reliability with a pixel portion having high definition with a large screen. According to a light emitting device of the present invention, on an insulator (24) provided between pixel electrodes, an auxiliary electrode (21) made of a metal film is formed, whereby a conductive layer (20) made of a transparent conductive film in contact with the auxiliary electrode can be made low in resistance and thin. Also, the auxiliary electrode (21) is used to achieve connection with an electrode on a lower layer, whereby the electrode can be led out with the transparent conductive film formed on an EL layer. Further, a protective film (32) made of a film containing hydrogen and a silicon nitride film which are laminated is formed, whereby high reliability can be achieved.

Abstract: An OLED display for improving white light emitting efficiency and simplifying a manufacturing process includes a plurality of pixels, each of the pixels having a transistor unit, a color filter unit and an organic light emitting device unit. The transistor unit converts signals from the outside into driving signals for driving an organic light emitting device unit. The organic light emitting device unit is composed of blue, red and green emission layers each having different areas. By passing white light through a color filer, the OLED display can realize full color.

Abstract: An electroluminescence display device including a substrate, a corrugated structure formed on the substrate, wherein the corrugated structure disperses light through diffraction and reflection; and a first electrode layer, a first insulation layer, a fluorescent layer, a second insulation layer, and a second electrode layer sequentially formed on the substrate to follow the shape of the corrugated structure.

Abstract: There is explained a plasma display panel that is adaptive for improving brightness uniformity of an entire panel. A plasma display panel according to an embodiment of the present invention has a width, a thickness and a gap of a driving electrode, barrier ribs, a black matrix and a dielectric layer etc. in a central area set differently from those in a peripheral area of the plasma display panel.

Abstract: An organic light-emitting diode (OLED) device, comprising: one or more OLED elements including first and second spaced-apart electrodes with one or more organic layers formed there-between, at least one organic layer being a light-emitting layer, wherein at least one of the electrodes is a transparent electrode, and wherein the light-emitting layer has a first refractive index; a first transparent encapsulating layer formed over the transparent electrode opposite the organic layer; a scattering layer formed over the first encapsulating layer opposite the transparent electrode; a second encapsulating layer formed over the scattering layer opposite the first transparent encapsulating layer; a transparent cover through which light is emitted having a second refractive index; and a low-index element having a refractive index lower than the first and second refractive indices formed between the second encapsulating layer and the transparent cover.

Abstract: An image display device is constituted such that a back substrate on which image signal lines, scanning signal lines and electron sources are arranged and a face substrate which has phosphor layers are hermetically sealed to each other by way of a frame body using a sealing material, and the inside of the image display device is formed into a vacuum. A length LSK of a second sealing region into which scanning signal lines hermetically penetrate is set larger than a length LDK of a first sealing region into which thin-film image signal lines hermetically penetrate and hence, it is possible to suppress the decrease of the degree of vacuum.

Abstract: A cathode (11; 20; 30) is provided for cold cathode lamps having the surface of the cathode at least partially coated with a layer of a getter material (15; 26; 31). The coating allows a reduction of the work function value of the cathode (11; 20; 30) and therefore a reduction of the power consumption of the lamp.

Abstract: A planar light source having a first substrate, a plurality of electrode modules, a second substrate, a dielectric spacer, a first phosphor layer, and a discharge gas is provided. The electrode modules are disposed on the first substrate. The second substrate is disposed above the first substrate. The dielectric spacer covers the electrode modules and is connected between the first substrate and the second substrate. The space between the first substrate and the second substrate is divided into a plurality of discharge spaces by the dielectric spacer. The first phosphor layer is disposed in the discharge spaces. The discharge gas is disposed in the discharge spaces. The coating area of the phosphor layer can be increased and cracks in the substrate can be prevented due to the simple structure of the planar light source.

Abstract: A Plasma Display Panel (PDP) having a structure that improves the brightness and the efficiency of the PDP includes: a first substrate; a second substrate arranged to face the first substrate; barrier ribs arranged between the first and second substrates to define a plurality of discharge cells together with the first and second substrates; at least one first discharge electrode arranged on the first substrate; a first dielectric layer arranged on the first substrate to cover the at least one first discharge electrode; an Electroluminescent (EL) light-emitting layer arranged at least on a portion of at least one second discharge electrode; and a discharge gas contained within the plurality of discharge cells.

Abstract: A plasma display panel that includes a front substrate, a rear substrate positioned in parallel to the front substrate, a plurality of address electrodes between the front and rear substrates, a plurality of display electrodes positioned perpendicularly to the plurality of address electrodes, and a plurality of barrier ribs between the front and rear substrates, the barrier ribs defining a plurality of discharge cells, and wherein each barrier rib includes at least one longitudinal portion positioned at an obtuse angle with respect to the rear substrate.

Abstract: Provided is a first substrate and a second substrate which face each other; a plurality of barrier ribs which define a space between the first and second substrates to form a plurality of cells and are located between the first and second substrates; a discharge gas filling the cells; a phosphor layer formed on the inner walls of the cells; a plurality of first electrodes formed on an inner surface of the first substrate; a plurality of second electrodes on an inner surface of the second substrate located in a direction crossing the first electrodes; a plurality of third electrodes formed on the first electrodes; and an electron accelerating layer which emits a first electron beam into the cells to excite the discharge gas when a voltage is applied to the first and third electrodes, and which is interposed between the first and third electrodes, wherein the electron accelerating layer is formed by printing an electron accelerating layer forming paste composition, drying the printed composition, and baking the

Abstract: Disclosed are a front filter of a plasma display panel capable of correctly forming an active display area of the plasma display panel, and a fabrication method thereof. To this end, a frame adhesive forming the active display area of the plasma display panel is formed on at least one thin film among a plurality of thin films of the front filter.

Abstract: A plasma display panel includes a first substrate and a second substrate, the first substrate and the second substrate being provided with a predetermined gap therebetween. Barrier ribs are formed in a non-striped pattern between the first substrate and the second substrate, the barrier ribs defining a plurality of discharge spaces. A plurality of address electrodes are formed on the first substrate along a direction (y), the address electrodes being formed within and outside discharge spaces. A plurality of sustain electrodes are formed on the second substrate along a direction (x), the sustain electrodes being formed within and outside discharge spaces. The address electrodes include large electrode portions provided within discharge spaces and small electrode portions provided outside the discharge spaces. If a width of large electrode portions is AW, a width of small electrode portions is Aw, and a distance between barrier ribs along direction (x) is D, AW is larger than Aw, and AW is 40-75% of D.

Abstract: A Plasma Display Panel (PDP) has a structure in which three discharge cells are adjacent to one another and are arranged in a triangular form, thereby forming one pixel, wherein in pixels arranged in a first direction, an average of 1.5 address electrodes are assigned to each pixel, which belong to the group of electrodes and have a specific angle in the first direction with respect to a surface parallel to the substrates, and at least four sustain electrodes pass through each pixel. In addition, even numbered or odd numbered electrodes of scan electrodes that are included in the sustain electrodes are sequentially connected to terminals of a scan electrode driving module, and the rest of the electrodes are sequentially connected to the next terminals of the scan electrode driving module.

Abstract: Disclosed is a plasma display panel. The plasma display panel includes discharge cells having the delta structure, in which a center portion of a dielectric layer provided at each lateral side of the delta-type discharge cell has a width larger than that of a peripheral portion of the dielectric layer, thereby improving the luminous efficiency of the plasma display panel.

Abstract: A plasma display apparatus having an improved structure so as to increase luminescence efficiency and uniformity and a method of manufacturing the display apparatus are provided. The display apparatus includes: a front substrate and a rear substrate facing each other; a plurality of first and second sustain electrodes formed on the front substrate and spaced apart from each other; and first and second electron emitting layers formed on the first and second sustain electrodes, respectively, emitting electrons received from the first and second sustain electrodes, and having a structure in which their thickness decreases as they approach a gap between the first and second sustain electrodes.

Abstract: A plasma display panel that includes a first substrate; a second substrate facing the first substrate; barrier ribs disposed between the first substrate and the second substrate and partitioning discharge spaces; pairs of discharge electrodes disposed between the first substrate and the second substrate in perpendicular to a direction in which the first substrate and the second substrate are disposed; dielectric layers disposed between the pairs of discharge electrodes in discharge spaces; and phosphor layers coated in the discharge spaces. The pairs of discharge electrodes perform a surface discharge perpendicularly so that the discharge easily spreads to overall regions of respective discharge cells.

Abstract: A plasma display panel includes two substrates, a plurality of barrier ribs defining a plurality of discharge cells between the two substrates, a plurality of pixels rows having a plurality of pixels with three discharge cells arranged in a triangular shape between the two substrates, and a plurality of address electrodes between the two substrates, such that an average of 1.5 address electrodes are assigned to each pixel in the pixels row.

Abstract: A method for sealing an automotive assembly comprising a first member having a tongue assembly and a second member having a groove adapted to receive the tongue assembly of the first member. The process comprises the following steps (i) in situ injection molding a silicone composition or thermoplastic composition onto the tongue assembly (20) and/or into the groove (9) (ii) curing the silicone composition or thermoplastic composition in place to form a gasket (21, 10) which is chemically and/or physically bonded to said tongue assembly (20) and/or groove (9) and (iii) sealing the automotive assembly by mechanically engaging the first member and the second member, at least one of which has a cured in place gasket produced in accordance with steps (i) and (ii) above.

Abstract: A high-pressure discharge lamp assembly has a discharge lamp (1) and a concave reflector (11) arranged around a longitudinal axis (30). The discharge lamp is closed in a gastight manner and comprises a first and second end portion (3, 4) and an ionizable gas filling, and in which a pair of electrodes (5, 6) is arranged. A first and a second current-supply conductor (7, 8) are connected to the pair of electrodes and issue to the exterior from the first and the second end portion, respectively. The first end portion of the discharge lamp extends through an opening (14) arranged in a center section of the reflector. A conduction member (9) is connected to the second current-supply conductor and extends through the opening in the center section of the reflector. The conduction member is connected to a contact member provided on a surface of the reflector facing away from the discharge lamp.

Abstract: A low-pressure discharge lamp includes a glass discharge vessel (1) which is substantially tubular in form and which is closed in a gas-tight manner on the ends thereof, a filling consisting of an inert gas mixture and quicksilver, in addition to an optional luminous coating on the inner wall of the discharge vessel (1). Two current supply inlets are respectively melted into the two ends of the discharge vessel (1), with a helical electrode secured thereto (5). The invention is characterized in that in order to increase the switching resistance of the lamp in a cold start operation, at least one other electrode (7,8) made of a conductive material is arranged in the region between the helical electrode (5) and the connecting end of the discharge vessel (1) and one end of the other electrode (7, 8) is electrically connected to one of the two current supply inlets (3, 4).

Abstract: The invention relates a high-pressure discharge lamp, which comprises: an outer bulb (1) in which a discharge vessel (11) is arranged around a longitudinal axis (22), the discharge vessel enclosing, in a gastight manner, a discharge space (13) provided with an ionizable filling, the discharge vessel having a first (2) and a second (3) mutually opposed portion forming a first and a second leadthrough through which a first (40) and a second (50) leadthrough conductor, respectively, extend to a pair of electrodes (6,7) arranged in the discharge space, a lamp base (8) of electrically insulating material supporting the discharge vessel via a first (4) and a second (5) current supply conductor, each having a weld with the respective first and second leadthrough conductor, forming a first and a second current path to the pair of electrodes, the lamp base also supporting the outer bulb, the outer bulb enclosing the first and second current supply conductors, the outer bulb being connected to the lamp base in a gas-ti

Abstract: A gas discharge lamp (2) is operated with an alternating current. A positive lamp current (Ip) is generated with a positive current intisity (Ip) for a positive duration (?p). A negative lamp current (IN) is genrated with a negative current intensity (IN) for a negative duration (?N). A duty cycle (D=?p/(?p+?N)) differs from 50%. A current ratio (R=Ip/IN) differs from 1.

Abstract: A power supply system has a power supply unit generating a power supply voltage signal, a voltage controller generating a first power supply control signal in response to the power supply voltage signal and a lamp-on/off signal, an inverter controller being driven in response to the first power supply control signal, and an inverter driving a lamp in response to a control signal from the inverter controller. The first power supply control signal prevents the inverter from being shut down. The voltage controller includes a comparator comparing a comparison voltage signal with a reference signal, a switch unit being turned on or off in response to the lamp-on/off signal and an output signal of the comparator, and a constant voltage generator providing a constant voltage signal as the first power supply control signal to the inverter controller.

Abstract: A system and method are disclosed for implementing a power source including a power amplifier that generates a radio-frequency power signal with an adjustable operating frequency. The power amplifier also generates a reference phase signal that is derived from the radio-frequency power signal. An impedance match provides the radio-frequency power signal to a plasma coil that has a variable resonance condition. A phase probe is positioned adjacent to the plasma coil to generate a coil phase signal corresponding to the adjustable operating frequency. A phase-locked loop then generates an RF drive signal that is based upon a phase relationship between the reference phase signal and the coil phase signal. The phase-locked loop provides the RF drive signal to the power amplifier to control the adjustable operating frequency, so that the adjustable operating frequency then tracks the variable resonance condition.

Abstract: The invention is directed to an arrangement for the generation of short-wavelength radiation based on a hot plasma generated by gas discharge and to a method for the production of coolant-carrying electrode housings. It is the object of the invention to find a novel possibility for gas discharge based short-wavelength radiation sources with high average radiation output in quasi-continuous discharge operation by which efficient cooling principles can be implemented using inexpensive and simple means in order to prevent a temporary melting of the electrode surfaces and, therefore, to ensure a long lifetime of the electrodes. According to the invention, this object is met in that special cooling channels for circulating coolant are integrated in electrode collars of the electrode housings.

Abstract: A lighting device with night light and human body sensing capability includes a first illumination device, a second illumination device, a sensor and a main body. The first illumination device is designed to illuminate a local predetermined area, and the second illumination device is designed to illuminate an entire predetermined area. The sensor comprises a first sensing member and a second sensing member. The first sensing member is to detect the illumination status of the predetermined area and to activate the first illumination device. The second sensing member is to detect a human body approaching and to activate the second illumination device. The main body is provided with fixtures to dismantle a cover for replacing the second illumination device.

Abstract: A handheld fluorescent task lamp comprising a housing assembly having a housing and a tubular lens body enclosing compact fluorescent bulbs, an elongated spine configured for slidingly supporting the lens body, and a resilient bulkhead for cushioning the compact fluorescent bulbs in the lens body; an electronic ballast circuit within the housing comprising a power supply, a self-starting electronic driver circuit operable to start and run at least first and second CFL bulbs; a bulb accommodation circuit that enables operation of the electronic ballast circuit with either starter type or non-starter type and regardless whether one or both CFL bulbs are connected to the driver circuit; and an illumination assembly, wherein the CFL bulbs are oriented with respect to each other such that an enhanced forward emission field is provided.

Abstract: A pulse width modulation (PWM) illumination control circuit with low visual noise for driving a light-emitting diode (LED) is provided. An illumination control pulse-generating unit is used to generate an illumination control pulse signal according to an illumination-adjusting signal. The duty cycle or frequency of the illumination control pulse signal varies within a predetermined scope for controlling a DC/DC converter to drive the light-emitting diode so that overall visual noise level of the PWM illumination control circuit is improved.

Abstract: A charging circuit has a battery 12, switching element 14, and resistor 16 for current detection arranged on the primary side of transformer 10. Diode 18 and capacitor 20 for storing electric power are arranged on the secondary side of transformer 10. In a normal state, the ON/OFF states of switching element 14 are repeated corresponding to output signals U1, U2 of two comparators 28, 30. However, if switching element 14 stays on or off longer than a prescribed period of time for some reason, the status of switching 14 will be switched forcibly by an auxiliary sequence of the logic parts in control logic 42.

Abstract: A voltage regulator supplies a drive voltage to a light emitting diode array. A current regulator has a plurality of current regulating terminals, correspondingly coupled to a plurality of constituting branches of the light emitting diode array, for controlling a plurality of drive currents respectively flowing through the plurality of constituting branches. An activation circuit causes the drive voltage to continuously rise until each of voltages at the current regulating terminals exceeds a reference voltage, thereby ensuring that each of the plurality of drive currents reaches a regulation current. Afterwards, a selection circuit selects a minimum voltage from all of the voltages at the current regulating terminals to serve as a feedback control signal for controlling the voltage regulator.

Abstract: The present invention provides a light source driver circuit for improving power conversion efficiency and avoiding a high cost due to the requirements of safety regulations. The light source driver circuit comprises a pulse width control circuit that uses an AC power supply to produce a square wave; a first transformer having a primary winding for inputting the square wave and a secondary winding for outputting a transformation square wave; a resonant circuit that inputs the transformation square wave for producing a resonance sine wave; and a second transformer having a primary winding for inputting the resonance sine wave and a secondary winding for outputting a transformation sine wave to drive a light source.

Abstract: A backlight assembly includes a switching section for switching on/off an input voltage so as to output a primary voltage in accordance with a control signal; and a voltage boosting section for boosting the primary voltage received at a primary side thereof to a secondary voltage at a secondary side thereof. The primary and secondary sides of the voltage boosting section are electrically isolated from each other. In a feedback link for supplying the control signal from the secondary side to the primary side, a signal isolation section is provided for both transmitting the control signal between and electrically isolating primary side and secondary side portions of the feedback link. Additionally or alternatively, a balancing circuit section is connected between the secondary side of the voltage boosting section and a plurality of lamps so as to uniformly supply an alternating current, generated by the secondary voltage, to the lamps, in order to uniformize the luminances of the lamps.

Abstract: A system and method for controlling power converters are disclosed. Briefly described, one embodiment is a method comprising communicating at least one first control signal to an alternating current/direct current (AC/DC) power converter from a multi-converter system controller, the AC/DC power converter and the multi-converter system controller residing in a power system electronics housing, and communicating at least one second control signal to a direct current/direct current (DC/DC) power converter from the multi-converter system controller, the DC/DC power converter residing in a power system electronics housing.

Abstract: A driving apparatus for a vibration type actuator is disclosed, which can boost the power source voltage and can reduce the cost and the size of the apparatus. The driving apparatus comprises an inductor being connected to a power source, a pulse generation circuit generating a first and second pulse signals that have a phase difference; a first switching element switching a supply operation for supplying the energy accumulated in the inductor to the electro-mechanical energy conversion element according to the first pulse signal; and a second switching element switching a discharge operation for discharging the energy accumulated in the electro-mechanical energy conversion element according to the second pulse signal.

Abstract: A vehicle-mounted drive control apparatus capable of effecting boosted escape running while preventing burnout when a reversible motor driven by way of a transistor bridge circuit encounters an abnormal load. A motor driven by a transistor bridge circuit reversibly drives a moving body between a reverse limit stopper and a forward limit stopper. A variable resistance produces an output signal related to the position of the moving body, and calibration information is read at the positions of the reverse limit position and forward limit position and saved from a microprocessor to a nonvolatile data memory in advance. When during normal drive running of the motor the motor stops at an intermediate position between the forward limit stopper and the reverse limit stopper, escape drive is carried out by the motor being driven alternately with a boosted current above its rated current and a resting current which is small or 0.

Abstract: A method for controlling the firing angle of a single-phase AC powered electric motor is provided which is triggered by at least one locking electronic switch, such as a triac (T1 and T4) located between the distribution voltage (UV) and at least one motor winding (A, B). According to said method, intervals are defined within which the triacs (T2 to T4) are to be fired according to the curve of the distribution voltage (UV) and the voltage (UEMK) induced in the respective winding in order to allow the motor to start as quickly and smoothly as possible and run quietly and at high efficiency.

Abstract: An Automatic Transfer Switch (ATS) having a switch configured to connect one of two sources to a load, a mechanical drive, an actuator, and a solid state control relay is disclosed. The mechanical drive is configured to drive the switch between a first position and a second position, the first position connecting the switch to the first source, and the second position connecting the switch to the second source. The actuator is in mechanical communication with the mechanical drive to cause the mechanical drive to move on command. The solid state control relay is responsive to an external signal and productive of a control signal, wherein the actuator is responsive to the control signal to cause the mechanical drive to move.

Abstract: A method and apparatus for controlling the speed of a DC electric motor receives a periodic commutation signal having a fixed duration on cycle and an off cycle. The commutation signal then is modified to form a periodic modified commutation signal having substantially the same period duration as the commutation signal. The modified commutation signal has a single on cycle per period. The method and apparatus then determine a desired speed of the motor, and vary the duration of the on cycle of the commutation signal to form the on cycle of the modified commutation signal. The on cycle of the modified commutation signal has a duration that is less than the fixed duration. By varying in this manner, the rotor rotates at substantially the desired speed.

Abstract: An actuating device for a movable component includes a reversible motorized drive for driving the movable component from a normal position into an open position, the movable component being uncouplable from the reversible motorized drive in its open position. The actuating device includes a driving element movably drivable by the reversible motorized drive and engages in a crank recess and extending along the path of motion of the movable component. A length of the crank recess corresponds at least to a path of motion of the driving element between its normal position and its open position or partially open position. After adjustably driving the movable component into its open position, the driving element may be returned by the reversible motorized drive into the normal position.

Abstract: In a method for improving commutation of the at least one phase (Pi) of an electric motor (1), the commutation angle (alpha) of the one or more phases (Pi) is continuously varied in accordance with the rotary frequency (f) of the electromagnetic energizing field (F) of the electric motor (1) and/or in accordance with an adjustable variable (S) which is characteristic of the driving power. A device (9) suitable for carrying out the method has a frequency converter 5) and a control unit (6) controlling the same and adapted to carry out the method.

Abstract: The invention relates to a variable speed drive for three-phase electric motor, comprising a rectifier module (10) supplying a rectified voltage (15) from a single-phase alternating current network, a voltage step-up module (40) supplying a regulated bus voltage (45), an inverter module (50) supplying a control voltage to the motor (M). The variable speed drive comprises a hybrid power-factor correction device which drives the voltage step-up module and which comprises a digital circuit (30) provided with a voltage step-up module supplying a correction signal based on a measurement signal of said bus voltage and an analogue circuit (20) supplying a driver signal (25) to the step-up module based on a measurement signal of said rectified voltage and based on said correction signal.