Abstract: Disclosed is a liquid crystal display panel which includes a switching circuit for converting an input voltage into an alternating current (AC) voltage, a transformer for boosting the AC voltage generated from the switching circuit, and a bypass capacitor part connected in parallel between an output terminal of the switching circuit and the transformer.

Abstract: An ignition circuit arrangement and method for a discharge lamp, with which there is associated a supply circuit for providing an ac supply voltage to the lamp, includes an ignition transformer which is connected to a trigger circuit on the primary side and to the lamp on the secondary side for transmitting an ignition pulse; an input energy source for the ignition trigger circuit; a first switch means in the trigger circuit and a control means which actuates the first switch means. To assist with the ignition process, an energy storage means controllable by the control means, in particular a voltage source controllable by the control means, is arranged in the supply circuit in series with the gas-discharge lamp. The controllable energy storage means serves to provide an additional energy supply during the ignition process beyond the actual ac supply for the lamp.

Abstract: A circuit arrangement for starting and operating at least one discharge lamp is provided.

Abstract: The present invention provides a dimming circuit for controlling the luminance of a light source and the method for controlling luminance. The dimming circuit comprises an inverter circuit and a driving circuit. The inverter circuit is electrically coupled to a light source to be controlled, to convert a direct current (DC) power input into an alternating current (AC) power. The inverter circuit comprises a transformer, a capacitor connected in parallel to the transformer, a plurality of switches located at both ends of the capacitor, and an oscillating circuit electrically connected to both ends of the transformer. The driving circuit is electrically connected to the inverter circuit, for regulating the AC voltage to control the time period that the light source is turned on.

Abstract: A driver circuit for operating one or more light emitting diodes(LEDs) is disclosed. An alternating supply current is generated and transformed to an alternating secondary winding voltage. Using rectifier means, such as diodes or synchronous switches, the alternating secondary winding voltage is converted to a substantially constant load current by using a buffer element. The buffer element comprises an output choke, such as an inductor. The power transferred from the power source to the LEDs may be controlled by frequency control of the alternating supply current.

Abstract: A backlight unit of a liquid crystal display includes a lamp, a balancing pattern capacitor electrically connected to the lamp for current balance, a transformer electrically connected to the lamp via the balancing pattern capacitor, a sensing pattern capacitor electrically connected to a terminal of the balancing pattern capacitor connected to the lamp to detect an abnormal driving state of the lamp, and a feedback circuit unit electrically connected to the sensing pattern capacitor to control the abnormal driving state of the lamp. A liquid crystal display device including the backlight unit is also disclosed.

Abstract: A flash lamp irradiation apparatus comprises at least one flash lamp having a bulb made of translucent material, two or more trigger members disposed along a tube axis of the at least one flash lamp, wherein voltage is simultaneously impressed to the two or more trigger members at lighting in order to emit light from the at least one flash lamp.

Abstract: A circuit structure for LCD backlight is disclosed in the present invention. The circuit structure includes an inverter topology, a current balance circuit, and a plurality of loads. The current balance circuit is coupled to the plurality of loads and capable of balancing current of N loads by using N/2?1 balance chokes. The circuit structure may further include a protection circuit which is coupled to the low voltage sides of the plurality of loads. The protection circuit is capable of sensing lamp voltages and providing a feedback signal to a controller. Furthermore, the protection circuit is composed of count-reduced and cost-competitive electronic elements.

Abstract: An oscillator generates a triangular wave signal whose inclination for charging a capacitor and inclination for discharging the same are the same and which is used to turn on/off FETs Qp1 and Qn1. A signal generation part generates first drive signal in a period shorter than a half period of the triangular wave signal to drive the Qp1, and generates a second drive signal having a pulse width substantially equal to that of the first drive signal and a phase difference of about 180 degrees with respect to the first drive signal, to drive the Qn1 and provide a current to the discharge tube in a direction opposite to the current driven by the first drive signal. Furthermore a pulse current generation circuit converts a synchronization pulse voltage signal into a pulse current that alternates between positive and negative current values.

Abstract: A soft start circuit generates a soft start voltage which changes over time when light emission of an EEFL is started. A pulse modulator receives a feedback voltage that corresponds to the output voltage of an inverter and the soft start voltage, and adjusts the duty ratio of a pulse signal PWM such that these two voltages match one another using a feedback operation. A striking control circuit monitors an error signal which is asserted when an abnormal state occurs. In a case in which the error signal has been asserted at a detection timing after the soft start voltage has reached a target voltage, the striking control circuit resets and restarts the soft start circuit. A driver controls the switching of the voltage at the primary coil of a transformer according to the pulse signal received from the pulse modulator.

Abstract: A power supply for supplying power to a lamp with functions of dimming, over-current protection, over-voltage protection, arcing protection, and low-temperature start-up is provided. When frequency of the output current exceeds a predetermined value, the power supply is turned off to accomplish a dimming goal and extend lifetime of the lamp. When abnormal statuses such as open-circuited status, short-circuited status, or arcing status occur, a surge current induced by the abnormal statuses may be eliminated to prevent the power supply from being damaged. A high-frequency current detection circuit is configured to detect whether a current supplied to the high-voltage load is a high-frequency current to prevent damage to the electronic elements in the high-voltage load. A current adjusting circuit is configured to adjust an alternating current outputted to a lamp set in response to an environment temperature to supply an adequate alternating current at a low temperature for starting the lamp set.

Abstract: An electronic ballast (10), for a gas discharge lamp (18), comprises a constant current source (14) and a switch (16). A transformer (60), for use in an igniter (90) for a gas discharge lamp (18, 40), comprises a core (62) which has interconnected legs (64, 66, 68), a first secondary winding (70) around a first leg (64), a second secondary winding (72) around a second leg (66), and a primary winding (74) around a third leg (66). An igniter (90) for a gas discharge lamp (18, 40) comprises a transformer (60) as described above and a drive circuit (92) for driving the primary winding (74).

Abstract: A starting circuit of a starting device for a high-pressure discharge lamp including an auxiliary light source has a diode placed in a forward direction in one of a pair of output lines which connect a main lighting circuit for generating AC voltage to the high-pressure discharge lamp and the auxiliary light source; a capacitor having one end connected to a cathode side of the diode; a boosting transformer including a primary winding, and a secondary winding having one end connected to an anode side of the diode or to the other output line and also having the other end connected to the other end of the capacitor; a high-frequency voltage generation circuit for continuously generating high-frequency voltage in combination with the primary winding; and a short-circuit switch for maintaining a short-circuit condition at both ends of the diode after the high-pressure discharge lamp is started.

Abstract: Control of delivery of current through one or more discharge lamps. Methods include alternately switching on and off switching elements that control a fluorescent lamp, in response to receiving input, until the brightness of the lamp decreases to a threshold. Further, methods include providing control signals at complementary duty cycles to further decrease the brightness and alternating the duty cycles of the signals applied to the filaments of the fluorescent lamp.

Abstract: From the individual small areas of a conductor pattern arranged on the back side of a circuit board, there are individually extended leader patterns, which are midway led by through holes to the surface side of the circuit board. The individual leader patterns led to the surface side are connected with a terminal portion on the low-voltage side through jumper pads. The desired small areas are enabled to function by shorting the jumper pads with solder. The individual small areas are constituted to have a capacity of 1 pF, when caused to function, and they have such a capacity as a pattern capacitor as is proportional to the number of the shorted jumper pads.

Abstract: An operating device for operation of at least one illuminant, such as one or more LEDs, includes first and second converters and first and second logic circuits. The first converter is supplied directly or indirectly with mains voltage, with a first reference potential. The second converter is galvanically isolated from the first converter, with a second reference potential for supplying a load circuit with the illuminant. The first logic circuit is for controlling the first converter, and the second logic circuit is for controlling the second converter. The first logic circuit and the second logic circuit are connected to one another, with potential isolation, via an interface.

Abstract: A transformer and a liquid crystal display apparatus having the transformer are provided. The transformer includes a bobbin having at least one first winding section, at least one second winding section, and at least one core insertion groove formed therein. The transformer also includes at least one coil wound around the first winding section and the second winding section with at least one core inserted into the core insertion groove.

Abstract: A light source driving device for driving a light source includes a power stage circuit, a transformer circuit, a control circuit, and a fault detecting circuit. The power stage circuit converts an external electrical signal to an alternating current (AC) signal. The transformer circuit is connected between the power stage circuit and the light source to convert the AC signal to a high voltage electrical signal adapted for driving the light source. The fault detecting circuit detects whether the light source is nonfunctional, and outputs a fault signal upon the condition that the light source is nonfunctional. The fault detecting circuit includes a voltage level comparison circuit and a variable-benchmark voltage circuit. The control circuit is connected between the fault detecting circuit and the power stage circuit to output a control signal to the power stage circuit based on the fault signal.

Abstract: An apparatus is disclosed that is capable of delivering substantially constant power to a luminous load in response to variation in the input voltage and variation in the environment temperature. The apparatus may be further adapted to vary the power supplied to the luminous load in response to changes in the input voltage produced by a dimmer circuit. In other words, during non-dimming applications, the apparatus is able to maintain substantially constant power supplied to the load even though the input voltage and environment temperatures are varying during typical daily operations. Additionally, if the input voltage is changed due to a user controlling a dimmer device to control the brightness of the luminous load, the apparatus is able to control the power delivered to the load in response to the dimmer device.

Abstract: A backlighting arrangement constituted of a driving transformer arrangement; a plurality of lamp pairs, each of the constituent lamps of the plurality of lamp pairs exhibiting a first electrical connection and a second electrical connection; and a plurality of balancing transformers, each comprising a primary winding and a secondary winding magnetically coupled to the primary winding, and each associated with a particular one of the plurality of lamp pairs, the primary winding of each of the plurality of balancing transformers serially connected between the second electrical connections of the constituent lamps of the associated lamp pair, the secondary windings of the plurality of balancing transformers serially connected in phase, with a first end of the serially connected secondary windings of the balancing transformers connected to one phase output of the driving transformer arrangement.

Abstract: A DC/AC inverter substrate includes a voltage abnormality detector circuit. All of a high voltage side detection sensor, a low voltage side detection sensor, and a high-voltage and low-voltage detection sensor in the voltage abnormality detector circuit are disposed without being electrically connected to a secondary side of a transformer or to a connection point. Those detection sensors are not damaged since overvoltage is not applied to the voltage abnormality detector circuit when abnormal discharge occurs because the detection sensors are not electrically connected.

Abstract: A voltage control apparatus (10) for an HID lamp includes a voltage control transformer circuit (20), and is connected between supply mains (22) and a high intensity discharge (HID) lamp. The HID lamp is started at full line voltage, and after a sufficient operating interval ensuring that the lamp has achieved a sustaining temperature, the operating voltage applied to the lamp is reduced, effecting considerable savings in energy use, with little or only an acceptably small decrease in light output from the lamp. Further, the voltage control apparatus include a circuit portion responsive to voltage transients on the AC line, and which effects restarting of the HID lamp in the event a voltage transient occurs which is sufficiently long (i.e., about ½ cycle) as to extinguish the HID lamp.

Abstract: A multi-lamp backlight apparatus is disclosed. The multi-lamp backlight apparatus includes 2N lamps, N balancing transformers, and a high-voltage power source. N is a positive integer and k is an integer index ranging from 1 to N. The kth balancing transformer among the N balancing transformers includes a first primary winding, a second primary winding, and a secondary winding. The first primary winding connects in series with the (2k?1)th lamp of the 2N lamps. The second primary winding connects in series with the first primary winding and the (2k)th lamp. The secondary winding corresponds to the first primary winding and the second primary winding. The high-voltage power source is connected between the first primary windings and the second primary windings.

Abstract: A lighting system for illuminating a chamber in a building includes a lighting fixture suitable for being mounted onto a surface of the chamber, so that light emitted by at least one CCFL device mechanically supported by the fixture illuminates the chamber. The one CCFL device includes at least one transformer. A driver adapted to be connected to a surface of the chamber is capable of converting input power from a power source to an AC power having a voltage in the range of about 5-400 volts and a current at a frequency in the range of about 1kc-100 kc. The at least one transformer is suitable for converting the AC power to an output power suitable for operating the at least one CCFL, causing the at least one CCFL to emit light.

Abstract: The combined ballast apparatus provides dual function, as both slave ballast and emergency battery ballast, without the expense of a dual installation of ballast onto or into a light fixture. The apparatus is further designed for best efficiency in mounting and in service and removal. The mount holes and quick clips provide for installation to existing fixtures without the need for screwdrivers, for example. The quick connects allow the apparatus to be quickly plugged and unplugged from a light fixture, without having to strip wires and use wire nuts or the like. If equipped with the apparatus and needing a ballast change, the fixture is serviced in a matter of perhaps ¼ to ? the time previously required, without the litter.

Abstract: The present invention discloses a light emitting device driver circuit and a method for driving a light emitting device. In the present invention, the secondary windings of a transformer provide positive and negative secondary voltages, so as to generate positive and negative output voltages. A light emitting device circuit is coupled between the positive and negative output voltages. As such, the specification to withstand high voltage for a device in the circuit is reduced.

Abstract: An electronic ballast powers at least one fluorescent tube or lamp which has a power source; a DC power supply having an input connected to the power source; an oscillator connected to an output of said DC power supply so as to be driven therefrom; a driver means; and a protection means that deactivates the oscillator when the output reaches a predetermined abnormally high voltage. The protection means includes a transformer; a plurality of windings disposed on the transformer, a delegated winding disposed on the transformer. The protection means includes a sample point for sampling voltage. The protection means deactivates the delegated winding disposed on the transformer for the magnetizing the transformer and stopping oscillation when the sample point reaches a predetermined abnormally high voltage.

Abstract: A lamp driving circuit is provided for controlling individual block luminances provided by corresponding locally dimmed blocks of a backlight unit of an LCD system where the backlight unit employs high voltage discharge lamps that each need to have an AC excitation signal of at least predetermined minimum high voltage level developed there across in order to generate light. The lamp driving circuit includes a plurality of isolation transformers and corresponding low voltage switch circuits. Each isolation transformer has primary windings and a secondary winding. The secondary winding is interposed between a high voltage AC power source and a corresponding one or more lamps. The equivalent circuit impedance of the secondary winding determines what voltage will develop across its respective lamps.

Abstract: In order to reduce the amount of wiring complexity involved in conventional starting devices for gas discharge lamps, the invention proposes a starting circuit arrangement in which the lamp, in order to provide an AC supply voltage (UN), is assigned a supply circuit, which has at least one inductor, which is arranged in series with the gas discharge lamp, and wherein the starting circuit arrangement comprises: a starting transformer, which is connected on the primary side to a starting triggering circuit and can be connected on the secondary side to the lamp for the transmission of a starting pulse; an input energy source for the starting triggering circuit; a first switch means in the starting triggering circuit; an electronic control device which drives the first switch means.

Abstract: A pulse width modulator generates a PWM signal whose duty ratio is feedback-controlled so that a detection voltage according to a current across a secondary coil of a transformer is brought close to a reference voltage. A logic control unit performs a switching control of the current across the primary coil of the transformer, based on the PWM signal outputted from the pulse width modulator. A first protection circuit detects a circuit failure of an inverter and stops the switching control of the inverter when the circuit failure continues for a predetermined duration of error detection time. A second protection circuit monitors a feedback voltage corresponding to an output voltage of the inverter, and lowers the reference voltage sets the duration of error detection time short when the feedback voltage is lower than a predetermined threshold voltage.

Abstract: A single-converter circuit-based LED driver circuit (10) with isolated multi-channel outputs is disclosed. The circuit (10) includes an IC control circuit (11), a plurality of isolated output channels (70, 74) each having an output current sensing and conditioning circuit (74, 90), and an output current regulation circuit (128). The output current regulation circuit (128) includes a voltage-sensing transformer winding (T4) that senses an output voltage level across a secondary side of the circuit (10), and a peak output current sensing component (156) that senses output currents from the isolated output channels and determines which channel has a highest current output. Additionally, the circuit (10) facilitates providing output current regulation when detected output voltage is below a predetermined threshold, and providing output current regulation when the detected output voltage is above the predetermined threshold.

Abstract: A projection device includes: a projector unit that has at least a light source and a projection optical system housed in a chassis; a control unit that is assembled with a chassis separate from the chassis of the projector unit; and a rotation support member that rotatably supports the projector unit and the control unit around a rotation axis that extends perpendicular to a surface of the chassis of the projector unit and a surface of the chassis of the control unit, with these surfaces facing to one another.

Abstract: A method is provided for driving at least one lamp unit, which is connected to an AC voltage power supply system. The method comprises modulating a control information item for the operation of the lamp unit onto the supplied AC voltage, decoding of the modulation received on the lamp unit side for reading the control information item and driving the light-emitting device in accordance with the control information item. Provision is made for a shunt to be produced in the line used for transmitting the control information item prior to or at the beginning of the modulation of the control information item. The disclosure also provides a lamp unit and a control device for implementing the method. The disclosure also provides a lighting system.

Abstract: A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source.

Abstract: To provide a low-cost self-excited inverter driving circuit exhibiting an excellent operational efficiency. A main inverter section is so constructed that a part of output signals is fed back by a resonance loop circuit to cause a self-excited oscillation to occur in the vicinity of a resonance frequency decided by leakage inductors and capacitors on the secondary side of a high voltage transformer, thereby performing an inverter operation. It is further arranged that a halt interval setting signal, which is generated by a triangular wave forming circuit and a control section, is applied to the main inverter section, thereby halting the inverter operation in accordance with the halt interval setting signal.

Abstract: An illumination system includes a master power supply providing power to several illumination modules. The master power supply is constructed and arranged to generate high-frequency and low-voltage electrical power provided to a primary wire forming a current loop. Each illumination module includes an electromagnetic coupling element and several light sources. The electromagnetic coupling element includes a magnetic core arranged to receive the current loop in a removable arrangement, and a secondary wire wound around the magnetic core to enable inductive coupling. The secondary wire is connected to provide current to the light sources that may be arranged in the illumination module as a DC load or an AC load.

Abstract: An inverter comprising a low-side switching element in series with a first primary winding; a high-side switching element in series with a second primary winding, where the combination of the low-side switching element and first primary winding is connected in parallel with the combination of the high-side switching element and the second primary winding; and a clamping capacitor having one terminal connected to the first primary winding and having a second terminal connected to the second primary winding. Other embodiments are described and claimed.

Abstract: The present invention relates to a lighting system comprising a base part (12) with at least one primary coil (18), and at least one light module (13, 14) with a secondary coil (26) adapted to inductively interact with the primary coil (18). The lighting system is characterized in that said base part (12) comprises a substrate (50) carrying said primary coil (18), the winding of which lying in one plane and forming a flat coupling area (16); the winding of the second coil (26) lies in one plane; and said light module (13, 14) comprises at least one light element (20) and a flat bottom surface, so that the light module (13, 14) is placeable with its flat surface on the flat coupling area (16).

Abstract: A lighting device which supplies power to an electrode of a discharge lamp to turn on the discharge lamp includes: a pulse generating circuit which produces a high-voltage pulse and applies the high-voltage pulse to the electrode; wherein the pulse generating circuit includes an inductor whose output end is connected with the electrode, and a capacitor connected with the output end of the inductor to produce free oscillation of current applied to the electrode in cooperation with the inductor.

Abstract: An AC inverter circuit supplies power to multiple lamps in an LCD backlight. Conventional AC power is used as direct input into a full wave rectifier that converts the input from AC to a DC reference voltage. A transformer driver, including a chopper, converts the DC reference voltage to a higher voltage AC which drives a step up transformer to produce a voltage sufficient to drive as many as six fluorescent lamps. The components/circuitry associated with the transformer's primary windings is optically isolated from the rest of the circuit.

Abstract: A method of igniting a gas discharge lamp (2) comprises the steps of first applying a plurality of high-voltage ignition pulses with a relatively low amplitude and subsequently applying high-voltage ignition pulses with a relatively high amplitude. Switching over from generating low-amplitude ignition pulses to generating high-amplitude ignition pulses may be done on the basis of counting the low-amplitude ignition pulses or on the basis of monitoring the duration of the period during which the low-amplitude ignition pulses are generated.

Abstract: The field of the invention is mainly that of light boxes used for the illumination of display screens using optical valves, notably for liquid crystal matrix displays also known as LCD screens. The light sources used are generally fluorescent tubes powered with a high voltage by devices comprising Royer electronic oscillators. These electronic oscillators do not allow wide dynamic ranges of luminance, which can be necessary for certain applications, to be easily attained. The oscillator according to the invention comprises an electronic device for discharging the stored electrical energy, said discharge device being controlled by an electronic control device using chopping modulation, thus enabling wide dynamic ranges of luminance to be attained.

Abstract: A transformer in this invention comprises substrates constructing a primary winding, substrates constructing the secondary winding, and a core member disposed around the substrates. The substrates defining the primary winding are provided with insertion holes for passing a middle leg portion of the core member, and patterned conductors having one turn. The transformer further comprises an interlayer connection member. The interlayer connection member is located inwardly of the patterned conductors of the substrates defining the primary winding. The interlayer connection member is located on the same side of the patterned conductors defining the primary winding. The interlayer connection member is configured to establish the electrical connection of the patterned conductors defining the primary winding.

Abstract: The high pressure discharge lamp lighting apparatus (10) includes a power circuit (20, 30, 40, and 50) and a starting circuit (60). The power circuit (20, 30, 40, and 50) includes a pair of output terminals (55 and 56) adapted to be respectively connected to a pair of electrodes (91 and 92) of a high pressure discharge lamp (90). The power circuit (20, 30, 40, and 50) is configured to apply an AC voltage for keeping the high pressure discharge lamp (90) turned on across the pair of the output terminals (55 and 56). The starting circuit (60) is configured to apply a starting pulse voltage across the pair of the electrodes (91 and 92) of the high pressure discharge lamp (90).

Abstract: A lighting device (8), which is provided with a cold cathode fluorescent tube (light source) (9) and a chassis (8a) that houses the cold cathode fluorescent tube (9), includes an inverter circuit (16) that includes a transformer (16a) to be connected to the cold cathode fluorescent tube (9) and drives the cold cathode fluorescent tube (9). The inverter circuit (16) drives the cold cathode fluorescent tube (9) using a frequency higher than a predetermined fundamental frequency during a predetermined period within a period in which the cold cathode fluorescent tube (9) is lit.

Abstract: The invention relates to a ballast for a high-pressure discharge lamp, in particular for a motor vehicle headlight lamp or a projection lamp, which ballast is, according to the invention, in the form of a Class E converter.

Abstract: A projector device employing ballast with a flyback converter is disclosed. For example, one embodiment comprises a lamp driver circuit including a power stage circuit including a flyback converter to output a direct current signal to a bridge circuit, the bridge circuit to reconstruct the direct current signal to an alternating current signal, a control circuit coupled with the power stage circuit and the bridge circuit, the control circuit to receive the direct current signal from the power stage circuit and to provide a frequency control signal to the bridge circuit, and a lamp igniter circuit comprising at least one charge pump and being coupled with the bridge circuit, wherein in response to the frequency control signal being provided to the bridge circuit, the bridge circuit is configured to increase the voltage of the alternating current signal provided to the lamp igniter circuit to power the lamp igniter circuit.

Abstract: A lighting device implemented through utilizing an insulating type piezoelectric transformer in driving light-emitting-diodes (LEDs), comprising at least said insulating type piezoelectric transformer connected to an LED module, a primary side of said insulating type piezoelectric transformer is used to receive a pulse voltage, and that is converted into an AC voltage in a piezoelectric voltage transformation way, and said AC voltage is output from a secondary side of said insulating type piezoelectric transformer to said LED module in proceeding with lighting function. Due to its various advantages of small leakage current, good insulation capability, high voltage endurance, low operation temperature, compact size, thin profile, high energy conversion efficiency, said insulating type piezoelectric transformer can be used to not only raise lighting efficiency, but also reduce overall size of said lighting device.

Abstract: A lighting apparatus comprises a plurality of light sources, a power conversion circuit, a plurality of load-driving coils and a feedback generation coil. The power conversion circuit generates a driving signal for the load-driving coils to generate substantially identical driving currents for driving every light source. Furthermore, the feedback generation coil generates a feedback signal based on the inductions of the currents flowing though the plurality of load driving coils.

Abstract: Provided is an inverter circuit capable of suppressing an increase in EMI level. In at least one embodiment, the inverter circuit includes: a drive circuit for outputting a pulse signal; a transformer for outputting a drive signal corresponding to the pulse signal to a fluorescent lamp, the transformer including a secondary winding having one end connected to the fluorescent lamp; a detection control circuit for detecting a detection signal corresponding to the drive signal supplied to the fluorescent lamp; a wiring line connecting another end of the secondary winding of the transformer and the detection control circuit; and a wiring line provided together with the wiring line so that magnetic fields generated are cancelled out each other.