Samsung Electro-Mechanics Co., Ltd.

Wits Co., Ltd.

Samsung Display Co., Ltd.

Hyo Young Kim

Young Seung Roh

Seung Won Park

Byoung Woo Ryu

Eun Young Shin

Jong Rak Kim

Sung Hun Oh

Sang Ho Cho

Jin Hwan Kim

In Wha Jeong

Se Joo Kim

Dong Woo Han

Jae Sun Won

Dong Seong Oh

Ki Hong Kim

Ji Hwan Yoon

Jae Hoon Hwang

Heun Seung Lee

Young Woon Choi

Tae Seok Ko

Young Gun Hong

Ku Yong Kim

Yun Ki Hong

Ye Ji Park

A wireless power transmitter includes: a power supply configured to supply a driving power; a first power transmitter including first bridge switching elements forming a first bridge circuit, and configured to receive the driving power to transmit a first power, wherein a magnitude of a first input voltage applied to the first bridge circuit is determined by a duty of at least one of the first bridge switching elements; a second power transmitter including second bridge switching elements forming a second bridge circuit, and configured to receive the driving power to transmit a second power, wherein a magnitude of a second input voltage applied to the second bridge circuit is determined by a duty of at least one of the second bridge switching elements; and a controller configured to output first and second power transmitting control signals respectively controlling the first bridge switching elements and the second bridge switching elements.

Wireless power transmitter

A wireless power transmitter includes: a first power transmitting unit including first switching elements forming a first bridge circuit, and configured to receive input DC voltage and transmit a first power by switching operations of the first switching elements; and a second power transmitting unit including second switching elements forming a second bridge circuit, and configured to receive the input DC voltage and transmit second power by switching operations of the second switching elements. The first power transmitting unit steps-up the input DC voltage according to a duty ratio of one or more of the first switching elements, and applies the stepped-up input DC voltage to the first bridge circuit. The second power transmitting unit steps-up or steps-down the input DC voltage according to a duty ratio of one or more of the second switching elements, and applies the stepped-up or stepped-down input DC voltage to the second bridge circuit.

A light emitting display device includes a substrate that includes a first pixel, a second pixel, a third pixel, and an infrared ray emission portion, the first pixel, the second pixel, and the third pixel representing different colors, a first electrode on the substrate, a second electrode that overlaps the first electrode, an emission layer between the first electrode and the second electrode, and an auxiliary layer between the first electrode and the emission layer. The emission layer may include a first emission layer in the first pixel and an infrared ray emission layer in the infrared ray emission portion, the auxiliary layer may include a first auxiliary layer in the first pixel, and the infrared ray emission layer and the first auxiliary layer may include the same material.

Light emitting display device

A wireless power transmission device including a resonant circuit magnetically coupled to a wireless power reception device and being configured to wirelessly transmit power, an alternating current (AC) generator including switches and being configured to receive a direct current (DC) voltage and to generate an AC current, according to a switching operation of the switches, to be supplied to the resonant circuit, and a variable capacitor connected to an output terminal of the AC generator and having a first capacitance, when a load state of the wireless power reception device is provided as a full load state and a second capacitance lower than the first capacitance, when the load state is provided as a light load state.

Wireless power transmission device and method of controlling the same

A wireless power transmitter includes: a converter including switching elements forming a bridge circuit, wherein the converter is configured to output an alternating current (AC) voltage including a frequency determined according to an operating frequency of at least one switching element among the switching elements; a resonator including an inductor and a capacitor, and configured to receive the AC voltage to wirelessly transmit power; and a controller configured to output control signals controlling the switching elements so that the converter performs a first mode operation in which an operating duty cycle is fixed and the operating frequency is varied, and an operation of the converter is switched from the first mode operation to a second mode operation in which the operating frequency is fixed and the operating duty cycle is varied, in response to the operating frequency reaching a first reference frequency.

Wireless power transmitter and method for wirelessly transmitting power

A wireless power transmitter includes: a converter including switching elements forming a bridge circuit and configured to output an alternating current (AC) voltage in response to control signals; a resonator including a resonant capacitor and a resonant coil, and configured to receive the AC voltage to transmit power wirelessly; and a controller configured to set a dead time at which a magnitude of the AC voltage is substantially zero in response to a signal received from a wireless power receiver.

A wireless power transmitter includes a common bridge circuit configured to apply a first alternating current (AC) voltage to a terminal of each of a first resonator and a second resonator of the resonators, a first sub-bridge circuit configured to apply a second alternating current (AC) voltage to another terminal of the first resonator while the first alternating current (AC) voltage is being applied to the terminal of the first resonator, and a second sub-bridge circuit configured to apply a third alternating current (AC) voltage to another terminal of the second resonator while the first alternating current (AC) voltage is being applied to the terminal of the first resonator.

Wireless power transmitter and method for controlling the same

A wireless power transmitter includes a wireless power controller configured to receive an alternating current (AC) voltage, to convert the AC voltage into a direct current (DC) voltage, and to generate an induced current from the DC voltage according to a switching control for a transformer; and a resonator configured to be resonated by the induced current to wirelessly output charging power.

Wireless power controller and wireless power transmitter using the same

There is provided a boost converter capable of reducing voltage stress within each element thereof, without using a separate loss snubber circuit, by clamping a voltage applied to an output diode to correspond to a difference between an input voltage and an output voltage. The boost converter includes a transformer including a primary winding receiving an input power and a secondary winding electromagnetically coupled to the primary winding and having a preset turn ratio therewith; a switching unit switching the input power transferred to the primary winding on and off according to a preset duty ratio; a stabilizing unit including an output diode rectifying the power outputted from the secondary winding to stabilize an output power; and a clamping unit clamping a voltage applied to the output diode to correspond to a difference between the input power and the output power during a switching on operation of the switching unit.

Boost converter for reducing voltage stress

The present invention relates to a light emitting device (LED) driving apparatus that constantly maintains the average current flowing onto a plurality of channels. The light emitting device (LED) driving apparatus includes: a LED light source unit in which at least one LED channel is connected in parallel; at least one current detector that is disposed on a low end of a LED channel of the LED light source unit to detect the current flowing onto respective LED channels; at least one channel current controller that generates control signal controlling the average current of the channels by comparing current detected from the channels with reference wave; and a switching element that controls the average current of the LED channels in a PWM scheme according to the control signals.

Light emitting device driving apparatus and method for driving the same

There is provided a backlight unit having a protection circuit using a center-tap, the backlight unit including: a current balancing unit including a plurality of primary coils individually transmitting the lamp driving power from an inverter unit to the lamps, and a plurality of secondary coils each formed of one conductor having a center-tap, and receiving an electromagnetically induced voltage from each of the plurality of primary coils, the one end and the center-tap of each of the plurality of secondary coils connected in series with the one end and the center-tap of the neighboring secondary coil to form at least one closed loop and maintain current transmitted to each of the lamps balanced; a sensing unit sensing a variation in current of the closed loop and a variation in current of the primary coil from the current balancing unit; and a determination unit determining whether each of the lamps performs an abnormal operation or not.

Backlight unit having protection circuit using center-tap

Provided is a power supply device including a power supply unit that supplies a driving voltage for driving at least one or more loads; a current balancing unit that maintains a current balance of the driving voltage supplied to the respective loads; a detection unit that detects currents flowing in the current balancing unit through electromagnetic induction so as to output a detection signal; and a control unit that receives the detection signal to judge whether the loads are opened or not and outputs a control signal for controlling the magnitude of the driving voltage.

Power supply device

There is provided a backlight unit that determines whether a lamp performs an abnormal operation by detecting a voltage that is induced in a power conversion transformer without using a complicated and expensive detection circuit. A backlight unit having a protection circuit using induced voltage detection according to an aspect of the invention includes an inverter part including a primary coil receiving power and at least one secondary coil converting the power from the primary coil to AC power set beforehand, a lamp part including at least one lamp receiving the AC power from the inverter part to emit light, a detection part including conductors detecting voltages electromagnetically induced in the secondary coil, and an abnormality determining part comparing detection voltages from the detection part with a reference voltage set beforehand.

Growing community of inventors

Suwon-si, South Korea

Hyo Young Kim