Patent
Serial configuration for dynamic power control in LED displays
TLDR
In this article, a power management technique in a light emitting diode (LED) system is described, which includes a plurality of LED driver connected in series, each LED driver configured to regulate the current flowing through a corresponding subset of the LED strings.Abstract:
A power management technique in a light emitting diode (LED) system is disclosed. The LED system includes a plurality of LED driver connected in series, each LED driver configured to regulate the current flowing through a corresponding subset of a plurality of LED strings. Each LED driver determines the minimum tail voltage of the LED strings of the corresponding subset, compares the determined minimum tail voltage with an indicator of a minimum tail voltage of one or more other subsets provided from an upstream LED driver in the series, and then provides an indicator of the lower of the two tail voltages to the downstream LED driver. In this manner an indicator of the minimum tail voltage of the plurality of LED strings is cascaded through the series. A feedback controller monitors the minimum tail voltage represented by the cascaded indicator and accordingly adjusts an output voltage provided to the head ends of the plurality of LED strings.read more
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Patent
Semiconductor integrated circuit and operation method thereof
Yuhei Kitagawa,Kazuyasu Minami +1 more
TL;DR: In this article, a DC-DC converter supplies an output voltage to a plurality of channels of a light emitting device array in common, and a logic unit executes a calibration operation which determines digital data for setting the minimum output voltage at the normal operation of all the channels by sequential updating of the digital data.
Patent
Continuous step driver
TL;DR: A light emitting diode (LED) lamp includes an LED cluster including LED groups arranged in series, a power source configured to provide an input power to the LED cluster, and a driving unit configured to adjust a number of the LED groups connected to a current path of a LED cluster in series as discussed by the authors.
Patent
LED control using modulation frequency detection techniques
TL;DR: In this paper, a light emitting diode (LED) controller for controlling a plurality of LED channels includes channel select circuitry, detection circuitry, and error processor circuitry, where the detection circuitry is configured to filter the composite bright signal and generate a selected brightness signal corresponding to a brightness of the selected LED channel at the probe modulation frequency.
Patent
LED driver with adaptive dynamic headroom voltage control
TL;DR: In this paper, a dynamic headroom regulation voltage control circuit monitors the headroom voltage at the bottom of each string of connected LEDs in a multi-channel LED and generates a reference voltage controlling each of the head room regulation voltages responsive to the LED bias reference voltage.
Patent
Power Source Control Method for a Multi-module LED Circuit and Related Control Device and LED Circuit
Jian-Shen Li,Chun-Liang Lin +1 more
TL;DR: In this article, a power source control method for a multi-module light-emitting diode (LED) circuit includes detecting a signal characteristics value according to a plurality of switching signals, being used for controlling the conduction of currents in the plurality of lighting modules.
References
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Patent
Organic light emitting diode methods and apparatus
TL;DR: In this article, an addressable controller is coupled to the first OLED and the second OLED for independently controlling a first intensity of the first radiation and a second intensity of a second radiation based on a network signal including lighting information.
Patent
Method and apparatus for controlling light emitting diodes
TL;DR: In this article, a light emitting code (LED) circuit includes a plurality of light emitting diodes connected in a hybrid parallel-series configuration, and a current regulating circuit that includes a current regulatory element connected to a first chain of the plurality of chains of LEDS.
Patent
Electronic circuits for driving series connected light emitting diode strings
TL;DR: In this paper, an error signal is provided to control a regulated output voltage signal generated by a controllable DC-DC converter for driving one or more series connected strings of light emitting diodes.
Patent
Single inductor serial-parallel LED driver
TL;DR: In this article, an LED driver circuit is disclosed that can drive a plurality of LED strings that are arranged in parallel, each LED string having a plurality component LEDs that are series-connected.
Patent
Light emitting element drive device and electronic device having light emitting element
TL;DR: In this paper, an electronic device having light emitting elements (21 to 26) driven by a high voltage such as LED is described, which includes a display unit (20) having a plurality of light emitting element sequences whose one end is supplied with high voltage higher than the power source voltage (Vdd) and a light-emitting element drive unit (10) having drivers (12 to 14) whose one-end is connected to terminals to which the other end of the plurality of LED element sequences is connected and which is turned on and off according to instruction signals (S