Patent application number | Description | Published |
20100207531 | COLOR MANAGEMENT FOR FIELD-SEQUENTIAL LCD DISPLAY - A method of color control for a backlight utilizing colored light emitting diodes (LEDs), the method constituted of: providing a plurality of colored LED strings constituted of at least three different colors; lighting each of the plurality of colored LED strings to provide a backlight; providing a period wherein none of the colored LED strings are lit; obtaining during the provided period when none of the colored LED strings are lit, an indication of an ambient light; obtaining during the provided period when the colored LED strings are lit, an indication of the optical output of the colored LED strings; and controlling the lighting of the provided plurality of colored LED strings responsive to the received indication of ambient light and the received indication of the output of the colored LED strings. Preferably, the method is performed in cooperation with an on-board color sensor. | 08-19-2010 |
20110080117 | DISTRIBUTED ARCHITECTURE VOLTAGE CONTROLLED BACKLIGHT DRIVER - A backlight system for light emitting diodes (LEDs), the backlight system constituted of: a controllable power source; a plurality of LED based luminaires arranged to receive power in parallel from the controllable power source; a plurality of driving circuitries, each of the plurality of driving circuitries arranged to control the light output of at least two of the plurality of LED based luminaires and further arranged to output information regarding the voltage drop of at least one of the at least two LED based luminaires controlled thereby, wherein the controllable power source is arranged to output a voltage whose value is responsive to the output information. | 04-07-2011 |
20110187283 | DIMMING INPUT SUITABLE FOR MULTIPLE DIMMING SIGNAL TYPES - A lighting circuit constituted of: a single dimming input; a pulse width modulation acceptance circuit arranged to convert a pulse width modulated dimming signal received at the single dimming input into a local dimming signal, the local dimming signal exhibiting a predetermined format; an analog voltage level acceptance circuit arranged to convert an analog voltage dimming signal received at the single dimming input into the local dimming signal exhibiting the predetermined format; and a luminaire driving circuit responsive to the local dimming signal. | 08-04-2011 |
20110248639 | SAMPLING EXTERNAL VOLTAGE WHICH MAY EXCEED INTEGRATED CIRCUIT MAXIMUM VOLTAGE RATING - An LED driver arrangement wherein a low voltage IC is arranged to sample the voltage at a terminal of each of the respective electronically controlled switches controlling a plurality of LED strings each receiving power from a single source, with the single source providing voltage in excess of the voltage rating of the IC. For each electronically controlled switch a controllable current source and an isolating unidirectional electronic valve is provided, the respective current source being enabled only when the respective associated electronically controlled switch is at least partially closed thereby ensuring that the respective isolating unidirectional electronic valve associated with the respective illuminating LED string conducts, and the voltage at the terminal of the respective electronically controlled switch is thus seen by the IC when the associated LED string is producing illumination, the voltage then being lower than the maximum voltage rating of the IC. | 10-13-2011 |
20140159688 | METHOD OF MAINTAINING AN OUTPUT VOLTAGE OF A POWER CONVERTER - A method of operating a power converter so as to maintain an output voltage, the method constituted of: receiving an input voltage; generating the output voltage from the input voltage responsive to at least one electronically controlled switch in communication with an inductor; deriving a gate voltage for the at least one electronically controlled switch of the power converter from the received input voltage; and deriving a gate voltage for the electronically controlled switch from the output voltage in place of the derived gate voltage from the input voltage responsive to a predetermined condition of one of the received input voltage and the generated output voltage. | 06-12-2014 |
20140217996 | HYSTERETIC CURRENT MODE CONTROL CONVERTER WITH LOW, MEDIUM AND HIGH CURRENT THRESHOLDS - A converter constituted of: an inductor; a plurality of electronically controlled switches; and a control circuitry arranged to operate in a buck-boost mode responsive to the output voltage of the converter being within a predetermined range of the input voltage of the converter, the control circuitry arranged in the buck-boost mode: responsive to a current flowing through the inductor being lower than a predetermined low current threshold, to control the switches to couple the inductor between the input voltage and a common potential; responsive to the current flowing through the inductor being greater than a predetermined medium current threshold, to control the switches to couple the inductor between the input voltage and the output voltage; and responsive to the current flowing through the inductor being greater than a predetermined high current threshold, to control the switches to couple the inductor between the output voltage and the common potential. | 08-07-2014 |
20150042300 | VOLTAGE REGULATOR WITH SWITCHING AND LOW DROPOUT MODES - A voltage regulator includes an input terminal, an output terminal, a control circuitry, a buck mode switching converter, and a low dropout regulator circuit. The buck mode switching converter is arranged to convert a voltage signal received at the input terminal to a first voltage signal at the output terminal responsive to a first predetermined signal output from the control circuitry. The buck mode switching converter includes an electronically controlled switch in communication with an energy storage element. The low dropout regulator circuit is coupled between the input terminal and the output terminal and includes a linear circuit and is arranged to control a voltage drop across the linear circuit so as to provide a second voltage signal at the output terminal responsive to a second predetermined signal output from the control circuitry. | 02-12-2015 |
20150304508 | LOAD BALANCING REVERSE POWER SUPPLY - A power supply unit includes a plurality of the interface ports and a plurality of power delivery units, each coupled to one of the interface ports and configured to extract power from data signals communicated over the interface ports by remote devices. A sharing circuit is coupled to each of the power delivery units for generating a power supply voltage from the power extracted from the data signals. A controller is configured to generate a communication line power loss estimate for each of the interface ports and configure the power delivery units to balance amounts of power supplied by each of the remote devices based on the communication line power loss estimates. | 10-22-2015 |