Abstract: A color controller for a luminaire constituted of: a thru-converter operative to convert an input signal to at least one luminaire drive signal; an illumination sampler arranged to sample an output from the luminaire and generate a representation thereof; and a feedback controller arranged to receive the output representation and generate the updatable conversion factor in cooperation with calibration luminance and color values, wherein the thru-converter operation is responsive to a trigger signal for defining a first and a second mode, the first mode for generating the luminaire drive signal for the luminaire responsive to the input signal being a frame luminance signal and target color signals and wherein the conversion to the at least one luminaire drive signal is responsive to an updatable conversion factor, and the second mode for generating the luminaire drive signal for the luminaire responsive to the feedback controller.

Abstract: 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.

Abstract: 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.

Abstract: A color manager for use with a luminaire constituted of a plurality of different colored light emitting diode based sub-luminaires arranged to produce a combined light. The color manager is constituted of a sampler arranged to output an electrical representation of the optical output of the luminaire, a converter coupled to the output of said sampler and operatively associated with a current selector arranged to select the driving current level of the luminaire from a plurality of current levels. The converter is arranged to convert said electrical representation to a pre-determined calorimetric system in cooperation with a calibration matrix whose values are selected responsive to the selected driving current level. The color manager further comprises a driver operatively associated with the luminaire, the converter and current selector and arranged to drive the luminaire in accordance with the driving current level as selected by the selector.

Abstract: A chipset for powering and controlling a plurality of light emitting diode (LED) strings. The chipset includes a controller having a pulse width modulating (PWM) functionality and a data transfer interface circuitry; and at least one dissipative active element array comprising a plurality of dissipative active elements. The dissipative active element array(s) are packaged to be thermally separate from the controller. The PWM functionality is arranged to individually pulse width modulate a current flow through each of the LED strings. Each of the plurality of dissipative active elements is associated with a particular one of the plurality of LED strings and is arranged to limit the current flow of the pulse width modulated current that flows through the particular LED string to a value, the value being responsive to a value output by the controller via the data transfer interface circuitry.

Abstract: 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.

Abstract: 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.

Abstract: A system for powering and controlling an LED backlight, the system comprising: a control circuitry; a controllable power source responsive to the control circuitry; and a plurality of LED strings receiving power from the controllable power source, the control circuitry being operative to control the output voltage of the controllable power source responsive to a function of an electrical characteristic of at least one of the plurality of LED strings.

Abstract: A secondary side post regulator arrangement for a plurality of LED strings. For each secondary winding, a first electronically controlled switch is provided arranged to control the power output, and a LED string is connected thereto. A second electronically controlled switch is further connected in series with the LED string, arranged to receive a PWM signal, thereby pulsing current through the LED string. A current sensing element is further provided outputting a voltage representation of the current through the LED string, and a synchronized sampling circuit is provided arranged to sample the voltage representation during the on period of the second electronically controlled switch. The sampled and held voltage representation is compared with a reference signal and fed back to control the first electronically controlled switch. The voltage output associated with each secondary winding is controlled, responsive to the reference voltage.

Abstract: 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.

Abstract: An optical sampling and control element for use with a luminaire exhibiting a cycle and a frame, the optical sampling and control element being constituted of a color sensor in optical communication with the luminaire; and a sampler connected to the outputs of the color sensor, the sampler comprising an integrator arranged to integrate the outputs of the color sensor over a predetermined period less than the frame.

Abstract: A fault detection mechanism for a LED string comprising a plurality of serially connected LEDs, the fault detection mechanism comprising: a control circuitry; and a voltage measuring means, in communication with the control circuitry, arranged to measure the voltage drop across at least one LED of the LED string, the control circuitry being operable to: measure the voltage drop, via the voltage measuring means, at a plurality of times, compare at least two of the measured voltage drops, and in the event the comparison of the at least two voltage drops is indicative of one of a short circuit LED and an open circuit LED, output a fault indicator.

Abstract: A system for powering and controlling an LED backlight, the system comprising: a control circuitry; a plurality of LED strings; a pulse width modulation functionality associated with the control circuitry and arranged to pulse width modulate a current flow through each of the plurality of LED strings; and a plurality of current limiters responsive to the control circuitry, each of the plurality of current limiters being associated with a particular one of the plurality of LED strings and operative to limit current flow of the pulse width modulated current there-through, the control circuitry being operative in the event of a thermal condition of one of the plurality of current limiters to reduce a duty cycle of the pulse width modulation functionality of the current flow through the one of the plurality of current limiters.

Abstract: 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.

Abstract: A backlighting system comprising: a color manager; a plurality of luminaires, each of the luminaires comprising a LED string and arranged to illuminate a particular portion of a display associated therewith; a color sensor arrange to receive light from one of the luminaires; and a plurality of thermal sensors each associated with a particular luminaire and in communication with the color manager, the plurality of thermal sensors being less than the plurality of luminaires, the color manager, responsive to the plurality of thermal sensors and the color sensor, being operable to calculate color coordinates for each of the plurality of luminaires.

Abstract: A chipset for powering and controlling a plurality of light emitting diode (LED) strings. The chipset includes a controller having a pulse width modulating (PWM) functionality and a data transfer interface circuitry; and at least one dissipative active element array comprising a plurality of dissipative active elements. The dissipative active element array(s) are packaged to be thermally separate from the controller. The PWM functionality is arranged to individually pulse width modulate a current flow through each of the LED strings. Each of the plurality of dissipative active elements is associated with a particular one of the plurality of LED strings and is arranged to limit the current flow of the pulse width modulated current that flows through the particular LED string to a value, the value being responsive to a value output by the controller via the data transfer interface circuitry.

Abstract: A color manager for use with a luminaire constituted of a plurality of different colored light emitting diode based sub-luminaires arranged to produce a combined light. The color manager is constituted of a sampler arranged to output an electrical representation of the optical output of the luminaire, a converter coupled to the output of said sampler and operatively associated with a current selector arranged to select the driving current level of the luminaire from a plurality of current levels. The converter is arranged to convert said electrical representation to a pre-determined calorimetric system in cooperation with a calibration matrix whose values are selected responsive to the selected driving current level. The color manager further comprises a driver operatively associated with the luminaire, the converter and current selector and arranged to drive the luminaire in accordance with the driving current level as selected by the selector.

Abstract: A method of controlling the luminance of a luminaire on an individual frame basis, without affecting a slow acting color loop controlling the color temperature of the luminaire, the method comprising: receiving a reference value representative of a target color; receiving a luminance signal defining the luminance of the luminaire per frame; adjusting a modulated signal driving the luminaire directly responsive to the received luminance signal, thereby controlling the luminance of the luminaire per frame; sampling the optical output of the luminaire per frame; comparing a value responsive to the sampled optical output with a value responsive to the received reference value to output a difference signal; and further adjusting the modulated signal driving the luminaire responsive to the compared value so as to reduce the difference signal.

Abstract: A color controller for a luminaire constituted of: a thru-converter operative to convert an input signal to at least one luminaire drive signal; an illumination sampler arranged to sample an output from the luminaire and generate a representation thereof; and a feedback controller arranged to receive the output representation and generate the updatable conversion factor in cooperation with calibration luminance and color values, wherein the thru-converter operation is responsive to a trigger signal for defining a first and a second mode, the first mode for generating the luminaire drive signal for the luminaire responsive to the input signal being a frame luminance signal and target color signals and wherein the conversion to the at least one luminaire drive signal is responsive to an updatable conversion factor, and the second mode for generating the luminaire drive signal for the luminaire responsive to the feedback controller.

Abstract: A method of controlling the output of a luminaire by receiving a first target signal associated with a first frame; generating a first light output control signal for an on time portion of the first frame, the light output control signal responsive to the received first target signal; sampling a light output during the on time portion of the first frame, the light output being responsive to the first light output control signal; receiving a second target signal associated with a second frame, the second frame following the first frame; comparing the received second target signal with the sampled light output of the on time portion of the first frame; and generating an error signal responsive to the comparing.