Stmicroelectronics S.r.l.

Stmicroelectronics (grenoble 2) Sas

Gaetano L'Episcopo

Giovanni Conti

Mario Antonio Aleo

Carmelo Occhipinti

Jonathan Steckel

An optoelectronic device includes a backlight panel illuminating a display panel. The backlight panel includes an array of light emitting pixels, each light emitting pixel having at least one subpixel with one or more light emitting diodes positioned on a substrate. The pixel further includes at least one photodetector positioned on the substrate and arranged to detect an amount of reflected light emitted by said subpixel and reflected by the display panel.

Optoelectronic device

Display elements, each having anode and cathode terminals, are arranged into rows and columns. Each row has an anode-line coupled to the anode terminals for its display elements. Each column has a cathode-line coupled to the cathode terminals for its display elements. A switch for each anode-line selectively couples that anode-line to a storage capacitor, and a switch for each cathode-line selectively couples that cathode-line to the storage capacitor. A display driver activates the row driver for a given row and the column driver for a given column. A switch driver closes the switch for the cathode-line for the given column, then opens the switch for that cathode-line. The display driver deactivates the row driver for the given row, after closing the switch for the cathode-line for the given column. The switch driver closes the switch for the anode-line for the given row.

High efficiency ghost illumination cancelation in emissive and non-emissive display panels

A non-emissive display includes a backlight controller sending a pulse during each sub-frame of a plurality of frames to row and column drivers that drive backlight zones. The row drivers count each pulse to keep a pulse count total, and reset the pulse count total when it is equal to a first number indicating how many row drivers are present. Each row driver activates its channels and waits for a next pulse if the pulse count total is not equal to the first number and if the pulse count total is equal to a second number indicating in which sub-frame that first driver is to be activated. Each row driver waits for a next pulse if the pulse count total is not equal to the first number and the second number. Each column driver activates its channel in response to receipt of each pulse.

System architecture for high density mini/micro LED backlight application

Driving a LED array includes determining total charge to be transferred to the LEDs during an image frame, and determining a number of drive pulses of equal width and amplitude that would drive the LEDs with nearly the total charge during display of the image frame. One of the drive pulses is modified so the drive pulses drive the LEDs with the total charge during display. If the width is greater than a minimum width and less than a maximum width, the LEDs are driven with the drive pulses. If the width is less than the minimum width and if an amplitude is greater than a minimum amplitude, the amplitude of the drive pulses is decremented. If the width is less than the minimum width and if the amplitude is equal to the minimum amplitude and if the number of drive pulses is greater than one, the number is decremented.

Method for hybrid pulse amplitude and width modulation in LED drivers for display panels

A method includes determining a number of drive pulses of equal width and amplitude that would drive LEDs with a total charge during a frame. If the width of the drive pulses is greater than a minimum-width and less than a maximum-width, the LEDs are driven with the drive pulses. If the width of the drive pulses is less than the minimum-width and an amplitude of the drive pulses is greater than a minimum-amplitude, decrement the amplitude of the drive pulses and recalculate the width of the drive pulses so each drive pulse has the decremented amplitude and recalculated width. If the amplitude of the drive pulses is equal to the minimum-amplitude, reduce the number of drive pulses and recalculate the width and amplitude of the reduced number of drive pulses. If the amplitude of the drive pulses is equal to the minimum-amplitude, the LEDs are not driven.

Method for hybrid pulse amplitude and width modulation in led drivers for display panels

Disclosed herein is a method of operating a display panel having a matrix of display elements. The method includes ordered steps of: (1) causing flow of current from a source of power, into an anode of a given display element, out of a cathode of the given display element to ground, wherein the flow of current into the anode and out the cathode to ground results in charging of a parasitic capacitance associated with the anode, (2) transferring charge from a storage capacitor to a parasitic capacitance associated with the cathode, and (3) stopping the flow of current, and then transferring charge from the parasitic capacitance associated with the anode to the storage capacitor.

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Catania, Italy

Gaetano L'Episcopo