Seoul Semiconductor Co., Ltd.

Hyun Gu Kang

Hye Man Jung

Sang Wook Han

Young Do Jong

Kang Nyung Lee

Sang Min Lee

Young Eun Yang

Hyung Jin Lee

Young Do Jung

Yoon Seok Lee

Oh Seok Kim

Snag Wook Han

Do Hyung Kim

Won Cheol Seo

Kyung Hee Ye

Dae Sung Kal

Seong Jin Lee

Jin Cheol Shin

You Jin Kwon

Won Il Kim

Do Hyoung Kim

An AC-driven LED lighting apparatus includes: a triac dimmer to generate a modulated AC voltage by modulating a phase of AC power according to a selected level of dimming; a rectifying circuit to generate drive voltage by full-wave-rectifying the AC voltage having the phase modulated by the triac dimmer; a dimming level detector to detect a dimming level according to the drive voltage; a phase cut reference setting unit for setting a phase cut reference value; and a LED driving module for constant-current-controlling a plurality of LED groups by comparing the detected dimming level with the phase cut reference value, wherein the light emitting element driving module comprises a LED current blocking unit for blocking a drive current supplied to the plurality of LED groups when the dimming level is lower than the phase cut reference value.

Alternating current-driven light emitting element lighting apparatus

A lighting apparatus includes a light-emitting diode (LED) array, a rectifying unit configured to rectify an alternating current (AC) voltage and to generate a driving voltage for the LED array, a switch control signal generation unit configured to generate a switching control signal depending on the driving voltage, the switching control signal including connection control signals and a compensation control signal, connection changing units configured to change a connection between the LEDs according to the connection control signals, and a light output compensation unit configured to generate a compensation voltage according to the compensation control signal, and selectively supply the compensation voltage to the LED array.

Backlight driving apparatus

An LED lighting apparatus according to exemplary embodiments includes a rectification circuit configured to rectify a modulated AC voltage to generate a drive voltage, an LED driving module connected to a plurality of LED groups and configured to apply a drive current to at least one of the plurality of LED groups according to a level of the drive voltage, and a dimming level detector configured to detect a dimming level corresponding to the drive voltage. The LED driving module is configured to compare the detected dimming level to a reference value and block the drive current based on a result of the comparison.

An LED luminescence apparatus is provided, which includes a rectifying unit rectifying an AC voltage and generating a rectified voltage; a plurality of LEDs connected in series to an output terminal of the rectifying unit; a plurality of switches having drain terminals connected to cathodes of the plurality of LEDs, respectively; and a switch control unit sensing current through a plurality of resistors connected to source terminals of the plurality of switches, respectively, comparing the sensed current with a set reference current, and outputting a voltage corresponding to a difference between the sensed current and the set reference current to a gate terminal of each of the plurality of switches.

LED luminescence apparatus

A light-emitting diode (LED) driving circuit configured to drive LED units includes a rectification circuit unit to receive an alternating current (AC) power voltage and rectify the AC power voltage to output a unidirectional ripple voltage, a pulse-width modulation (PWM) signal generation unit to generate PWM decision signals. The PWM signal generation unit is configured to sequentially drive the LEDs according to the PWM decision signals.

LED luminescence apparatus and method of driving the same

An exemplary embodiment discloses a light-emitting diode (LED) driving circuit including an LED driving module configured to provide a first driving voltage to an LED light emitting module including a first LED group to an n-th LED group, n is an integer which is equal to or larger than 2, and sequentially drive the first LED group to the n-th LED group depending on a voltage level of the first driving voltage and a second driving voltage providing module configured to store some of the first driving voltage and selectively provide a second driving voltage to some of the LED groups other than at least the first LED group to an m-th LED group among the LED groups in a Vcompensation section, 1&#x2266;m&#x2266;n&#x2212;1, according to a control of the LED driving module.

LED driving circuit for continuously driving LED, LED lighting device comprising same and driving method

An LED driving circuit package includes a rectification unit to receive an AC power voltage and rectify the AC power voltage to generate a ripple voltage, an LED driving switching unit including a plurality of switch units and a plurality of current control units. The LED driving circuit package further includes a low voltage control unit including a circuit power supply unit to generate low voltage power, a voltage detection unit to detect a magnitude of the ripple voltage, a reference frequency generation unit to generate a reference frequency, and a reference pulse generation unit to generate a reference pulse for controlling the operation of the LED driving switch unit according to the reference frequency and a magnitude of the voltage detected by the voltage detection unit.

LED driving circuit package

A backlight driving apparatus that drives a backlight unit having a plurality of LEDs is provided, which includes a rectifying unit rectifying an AC voltage and generating a driving voltage for the plurality of LEDs, a plurality of connection changing units changing connection relations between the plurality of LEDs depending on a level of the driving voltage, and a light output compensation unit generating a compensation voltage using the driving voltage and selectively supplying the compensation voltage to the plurality of LEDs.

Disclosed herein are a light emitting diode (LED) driving apparatus and driving method for continuously driving an LED. According to the present invention, an LED driving apparatus and driving method for continuously driving an LED capable of compensating for a light output of an LED lighting using an energy chargeable and dischargeable element and/or circuit are proposed.

LED driving apparatus and driving method for continuously driving LED

A light-emitting diode (LED) dimmer for an LED lighting device, including a power switch, a drive voltage supply, and a LED light-emitting unit. Operating zones of the LED lighting device are changed in accordance with the switching of the power switch, and a dimming level for a next operating zone is determined on the basis of the dimming level and time while the power switch was on during the previous operating period.

LED dimmer, LED lighting device comprising same, and method for controlling dimming of LED lighting device

An LED luminescence apparatus includes a plurality of LED units connected in series which are configured to receive a unidirectional ripple voltage, a plurality of switch units, one end of each being connected to the cathode of one of the plurality of LED units, a plurality of constant current control circuit units, one end of each being connected to an another end of a respective switch unit to receive a current from the respective switch unit, each of the constant current control circuit units being configured to output a current control signal to the respective switch unit to control a magnitude of the received current to have a specific value, and a current comparison unit to receive currents flowing from the plurality of switching units, and generate a plurality of switching control signals for the respective switch units to sequentially drive the plurality of constant current control circuit units.

A light emitting device comprises a first light emitting unit and a second light emitting unit connected in series with each other, and a PTF unit connected in parallel with the first light emitting unit and in series with the second light emitting unit. Each of the first light emitting unit and second light emitting unit comprises at least one LED. The PTF unit allows the second light emitting unit to be operated before operation of the first light emitting unit upon application of an AC voltage source. The light emitting device reduces total harmonic distortion and flickering, and improves power factor and optical efficiency. A driving circuit of the light emitting device is also disclosed.

Light emitting device and driving circuit thereof

A light-emitting diode (LED) driver used to power at least one LED with an alternating current (AC) voltage source is provided. The LED driver includes a rectifying unit applying N-fold higher voltage than the voltage from the AC voltage source to the LED. The rectifying unit includes a first charging unit to charge a first voltage, and a second charging unit to charge a second voltage. The first voltage includes the voltage at the AC voltage source during a first half-cycle of one AC voltage cycle, and the second voltage includes the first voltage and the voltage at the AC voltage source during the second half-cycle of the AC voltage cycle. Accordingly, the LED driver may improve light-emitting efficiency and reduce flicker of LEDs.

Light-emitting diode driver

Exemplary embodiments of the present invention relate to a dimmer for a light emitting device using an alternating (AC) voltage source. The dimmer includes a switch to be switched in response to a switching control signal and to deliver an AC voltage of an AC voltage source to the light emitting device, a current detector to detect an electric current to be provided to the light emitting device and to output a current detection signal, and a controller to output the switching control signal in response to a dimming control signal and the current detection signal.

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Ansan-si, South Korea

Hyun Gu Kang