Patent application number | Description | Published |
20090058467 | PHASE DETECTION APPARATUS - There is provided a phase detection apparatus that can accurately detect a phase difference between an input signal and a reference signal even when the input signal and the reference signal have different duty cycles. A phase detection apparatus according to an aspect of the invention may include: a pulse generation unit generating a first pulse signal on an edge of an input pulse signal, and a second pulse signal based on an edge of a reference pulse signal having a predetermined phase; and a detection unit detecting a phase difference between the first pulse signal and the second pulse signal from the pulse generation unit. | 03-05-2009 |
20090058793 | BACKLIGHT UNIT FOR SYNCHRONIZATION WITH AN IMAGE SIGNAL FOR LIQUID CRYSTAL DISPLAY - A backlight unit for synchronization with an image signal for a liquid crystal display (LCD), which can synchronize frequencies of a lamp driving signal and a lamp brightness signal with frequencies of a horizontal synchronization signal and a vertical synchronization signal, which are image signals used in an LCD panel. The backlight unit includes a synchronization part generating a first synchronized signal synchronized with a horizontal synchronization signal having a preset frequency, and a second synchronized signal synchronized with a vertical synchronization signal having a frequency different from the frequency of the horizontal synchronization signal, and a signal generation part generating a lamp driving signal for driving a lamp according to the first synchronized signal and a lamp brightness signal for controlling brightness of the lamp according to the second synchronized signal. | 03-05-2009 |
20090128055 | APPARATUS FOR DRIVING LIGHT EMITTING ELEMENT - Provided is an apparatus for driving a light emitting element. The apparatus includes a power unit, a light emitting element array, a constant-current circuit unit, and a voltage limiting circuit unit. The power unit supplies driving power. The light emitting element array includes a plurality of light emitting elements connected in series between an anode terminal connected to the power unit and a cathode terminal. The constant-current circuit unit maintains a constant current flowing through the light emitting element array according to a first tuning voltage. The voltage limiting circuit unit is connected between the cathode terminal of the light emitting element array and the constant-current circuit unit, and divides a total voltage applied between the cathode terminal of the light emitting element array and a ground according to a second tuning voltage to limit a voltage applied to the constant-current circuit unit below a predetermined voltage. | 05-21-2009 |
20100109547 | LCD BACKLIGHT INVERTER - Disclosed is a liquid crystal display (LCD) backlight inverter. The LCD backlight inverter includes a lamp open detection unit outputting a first open detection voltage for a preset time period when it is determined that a predetermined lamp is open, based on a current voltage corresponding to the current of the predetermined lamp of a plurality of lamps, a first open determination unit outputting an open detection signal when the first open detection voltage is input, a second open determination unit outputting a protection signal when it is determined that all of the plurality of lamps are open based on detection voltages of the plurality of lamps, a temporary protection determination unit outputting a frequency change signal when both the open detection signal and the protection signal are input, and an operating frequency control unit changing an operating frequency to a preset protective frequency according to the frequency change. | 05-06-2010 |
20100109563 | APPARATUS FOR DRIVING MULTI-LIGHT EMITTING DEVICES - An apparatus for driving multi-light emitting devices that drives a multi-channel light emitting unit having a plurality of light emitting channels connected in parallel with each other, each of which has a plurality of light emitting devices connected in series with each other according to an aspect of the invention may include: a DC/DC converter generating a driving voltage; a current control unit having a plurality of current sources connected between cathodes of the plurality of light emitting channels and a ground; a minimum voltage selection unit detecting a minimum detection voltage among the plurality of detected voltages at the cathodes of the plurality of light emitting channels; a first error detection unit detecting an error voltage determined by the difference between the minimum detection voltage and a predetermined first reference voltage; and a feedback coupling unit supplying the input voltage according to the error voltage and the driving voltage. | 05-06-2010 |
20100141300 | INVERTER DRIVER INTEGRATED CIRCUIT - An inverter driver integrated circuit (IC) includes a control signal generator generating a first control signal and a second control signal by use of a pulse width modulation oscillator signal, a comparator comparing a half-wave rectified signal of a lamp feedback signal fed back from a lamp with a preset reference signal to output a lamp state signal, a first sensor receiving the lamp state signal and the second control signal to output a first sensing signal, and a second sensor receiving the first sensing signal and the first control signal to output a second sensing signal. | 06-10-2010 |