Patent application number | Description | Published |
20100244713 | ILLUMINATION APPARATUS USING LIGHT EMITTING DIODE - An illumination apparatus using a light emitting diode is directly driven by an alternating current (AC) power source, displays colors and simultaneously controls a color's brightness level. The illumination apparatus includes a power terminal unit to which an AC power source is applied; a variable current unit connected to one end of the power terminal unit, dividing current provided from the power terminal unit into a plurality of current levels, and including first, second and third variable current units controlling the plurality of divided current levels, respectively; and a light emitting unit including red, green, and blue light emitting units, respectively disposed between the first variable current unit and the other end of the power terminal unit, between the second variable current unit and the other end of the power terminal unit, and between the third variable current unit and the other end of the power terminal unit. | 09-30-2010 |
20110156606 | LIGHT EMITTING DIODE DRIVER - There is provided a light emitting diode (LED) driver removing signal interference by varying a switching frequency within a preset range. The LED driver includes a power supply section switching input power and supplying driving power to at least one LED; a switching control section controlling the switching of the power supply section according to a clock signal being supplied; and a clock signal generation section supplying the clock signal having a preset variable frequency range to the switching control section. | 06-30-2011 |
20120032991 | ORGANIC LIGHT EMITTING DIODE DRIVER - There is provided an organic light emitting diode driver being capable of compensating for pixel deterioration in real time during the driving of pixels by selectively compensating pixels, requiring compensation, for the deterioration thereof. The organic light emitting diode driver includes a converting unit converting input data into compensation data used to selectively compensate for pixel deterioration depending on whether the input data has been calibrated or not; a driving unit driving pixels of a pixel unit based on the compensation data from the converting unit; and a compensating unit providing the converting unit with a deterioration compensation signal based on deterioration information obtained from a pixel driven by the driving unit. | 02-09-2012 |
20120044235 | ACTIVE MATRIX ORGANIC LIGHT EMITTING DIODE DISPLAY - There is provided an active matrix organic light emitting diode display, including a data driver converting pre-prepared correction data into an analog correction signal and generating a driving signal according to the analog correction signal, a selector selecting a charging path for programming, according to the driving signal in a preset programming period and selecting a deterioration detection path in a preset emission period, a pixel unit including an organic light-emitting diode connected between a power supply receiving power and a ground, charging a value corresponding to the correction data according to the driving signal in the programming period, and allowing current to flow to the organic light-emitting diode according to the charged value in the emission period, and an ADC detecting deterioration voltage having deterioration information of the organic light-emitting diode of the pixel unit in the emission period. | 02-23-2012 |
20120044269 | ORGANIC LIGHT EMITTING DIODE DRIVER - There is provided an organic light emitting diode driver capable of compensating for pixel deterioration in real time during the driving of pixels by selectively compensating pixels, requiring compensation, for the deterioration thereof, and precisely setting calibration data by removing an IR drop across a transistor, employed as a switch in the pixels, by calculating a difference between at least two representative values of different gray scale ranges among predetermined gray scale ranges. | 02-23-2012 |
20120044271 | ACTIVE MATRIX ORGANIC LIGHT EMITTING DIODE DISPLAY HAVING DETERIORATION DETECTION FUNCTION IN PROGRAMMING PERIOD - There is provided an active matrix organic light emitting diode display including: a data driving unit converting previously prepared correction data into a correction signal and generates a driving signal according to the analog correction signal; a pixel unit having an organic light emitting diode (OLED) between first and second power supply terminals receiving first and second powers, respectively, charging a value corresponding to the correction data according to the driving signal in a predetermined programming period, detecting the driving signal in order to detect deterioration, and allowing current to flow through the OLED according to the value charged in the predetermined programming period in a predetermined holding period; and an ADC detecting deterioration voltage corresponding to the driving signal having deterioration information of the OLED of the pixel unit in the holding period. | 02-23-2012 |
20120056866 | ACTIVE MATRIX ORGANIC LIGHT EMITTING DIODE DISPLAY HAVING RESET FUNCTION - There is provided an active matrix organic light emitting diode (AMOLED) display including a driver generating analog driving signals based on previously prepared driving data; a pixel unit including an organic light emitting diode connected between first and second power supply terminals receiving first and second power, respectively, charging values equivalent to the driving data according to the driving signals and simultaneously detecting the driving signals in order to detect deterioration in a preset tracking period, allowing current to flow through the organic light emitting diode according to the values charged in the tracking period in a preset holding period, and setting a reset period between the holding period and a tracking period subsequent thereto to reset the charged values; and an ADC detecting a deterioration voltage corresponding to the driving signals having deterioration information of the organic light emitting diode of the pixel unit in the tracking period. | 03-08-2012 |
20120074859 | DRIVER FOR LIGHT EMITTING DIODES - There is provided a driver for light emitting diodes capable of differently setting duties in which driving current flows depending on respective light emitting diode (LED) channels according to a voltage deviation between the LED channels in order to reduce heat generated due to the voltage deviation between the LED channels. The driver for LEDs includes: a detecting unit detecting a voltage drop generated in each of a plurality of LED channels receiving driving power having a preset voltage level; a converting unit converting detected analog values from the detecting unit into digital values; and a driving unit differently setting switching duties in which driving current flows in each of the plurality of LED channels according to the digital values from the converting unit to drive the plurality of LED channels. | 03-29-2012 |
20120086515 | RELAXATION OSCILLATOR - There is provided relaxation oscillator. The relaxation oscillator includes: a ramp wave generator generating ramp waves by a complementary operation between a first capacitor module charged and discharged according to a first switching signal and a second capacitor module charged and discharged according to a second switching signal; a negative feedback circuit unit generating a compensation voltage for compensating errors with reference voltage by being fedback with the ramp waves; and a switching signal generator generating the first switching signal controlling the charging and discharging of the first capacitor module and the second switching signal controlling the charging and discharging of the second capacitor module from the compensation voltage and the ramp waves. As a result, the present invention can generate ramp waves having a stable frequency while preventing a frequency from being changed due to a delay or an offset of the comparator. | 04-12-2012 |
20120146530 | LIGHT EMITTING DIODE DRIVER - The present, invention relates to a light emitting diode driver that integrates a light emitting diode control function and a power switching control function at a secondary side insulated from a primary side in a power supply circuit, without using a photo coupler to control power switching at the primary side. | 06-14-2012 |
20120161662 | DIGITAL PWM GENERATOR AND APPARATUS FOR DRIVING LIGHT EMITTING DEVICE - There is provided a digital PWM generator according to a first exemplary embodiment of the present invention including: an A/D converter dividing a predetermined reference voltage into a plurality of sections corresponding to a predetermined first set value, searching a section to which the magnitude of an input voltage Vin corresponds, among the plurality of sections, and converting a value corresponding to the searched section into a digital signal; a frequency selector providing a counting number by counting a predetermined high-speed counting clock during a one-cycle section of a predetermined reference clock; and a PWM signal generator converting the digital signal from the A/D converter into a ratio value corresponding to a ratio for the reference voltage and generating a PWM signal having a controlled duty ratio of the reference clock by using the ratio value and the counting number from the frequency selector. | 06-28-2012 |
20120299490 | LED CIRCUIT - There is provided an LED circuit. The LED circuit may include 2N+2 light emitting units connected between a 2K−1-th node and a 2K-th node among 4N+4 (N is a natural number) nodes including a first node supplied with input voltage (K is all natural numbers equal to or smaller than 2N+2); 2N+2 switches connected between a 2K-th node and a ground (K is all natural numbers equal to or smaller than 2N+2); 2N+1 switches connected between a 2L−1-th node and a 2L+1-th node and 2N+1 switches connected between a 2L-th node and a 2L+1-th node (L is all natural numbers equal to or smaller than 2N+1); and N switches connected between the first node and a 4M+1-th node (M is all natural numbers equal to or smaller than N). | 11-29-2012 |
20120299497 | LED CIRCUIT - There is provided an LED circuit including a light emitting unit including a plurality of light emitting diodes; and a switching unit switching to apply only positive voltage of an AC power supply to an anode of the light emitting unit. Through this, the LED circuit can reduce complexity of a driving circuit. Further, lifespan and efficiency of the LED circuit may be improved since an electrolytic capacitor and a bridge circuit are not used. Further, any one light emitting diode may be prevented from determining the lifespan of all of the light emitting diodes since all of the light emitting diodes are driven at all times, thereby improving the lifespan of the light emitting diode. | 11-29-2012 |
20120306396 | LED DRIVING APPARATUS AND METHOD - There are provided an LED driving apparatus and an LED driving method thereof. The LED driving apparatus includes: a light emitting unit including one or more LEDs, a rectifying unit rectifying an input signal to generate a first signal; a signal conversion unit inverting a waveform of a first signal to generate a second signal; and an operation unit arithmetically operating the first and second signals. A plurality of AC signals each having a different waveform are arithmetically operated to generate a signal having a small amount of a ripple component, and an LED is driven by the signal, thus preventing a lifespan of the LED from being shortened by omitting a smoothing electrolytic capacitor, one of main causes shortening the lifespan of an LED driving circuit. | 12-06-2012 |
20120319609 | LIGHT EMITTING DIODE DRIVER HAVING OFFSET VOLTAGE COMPENSATING FUNCTION - There is provided a light emitting diode (LED) driver having an offset voltage compensating function compensating for an offset voltage generated at the time of driving of an LED, the LED driver including: a driving unit detecting a current flowing in an LED unit having at least one LED, as a voltage and controlling the current flowing in the LED unit according to a comparison result between the detected voltage and a reference voltage having a preset voltage level; and an offset compensating unit integrating a voltage difference between the detected voltage and the reference voltage and adding or subtracting a compensating current according to an integration result to thereby compensate for an offset. | 12-20-2012 |
20130033191 | LIGHT EMITTING DIODE DRIVING DEVICE AND METHOD THEREOF - There are provided a light emitting diode (LED) driving device allowing for an increase in an LED driving rate by discharging a charge stored in a capacitor during a certain period of time and a method thereof. The LED driving device includes: a driving unit detecting a current, as a voltage, the current flowing across an LED unit having at least one LED, controlling the current flowing across the LED unit according to a comparison result between the detected voltage and a reference voltage having a pre-set voltage level, and having a capacitor stabilizing an operation of the LED unit when the LED unit is driven; and a discharging unit discharging a charge stored in the capacitor during a pre-set discharge time when the LED unit is initially driven. | 02-07-2013 |
20130162144 | LIGHT EMITTING DIODE DRIVING APPARATUS - Provided is an LED driving apparatus. The LED driving apparatus includes a plurality of LED groups each comprising one or more diodes, a switch group comprising a plurality of switch units connected respectively to the LED groups to drive the connected LED group when a control signal is activated, and a switch controlling unit configured to compare an input voltage of the LED groups with an output voltage of the LED groups, calculate a comparison value, and generate the control signal according to the comparison value. Accordingly, the LED driving apparatus drives the LED groups selectively according to the difference between the input voltage of the LED group and the output voltage of the LED group, thereby overcoming the problem of heat generation by forward voltage distribution. | 06-27-2013 |