Abstract: A method and an apparatus for operating an LED display are provided. The method includes: storing Nth scan line data in a line buffer; storing the Nth scan line data in a frame buffer; displaying the Nth scan line data stored in the line buffer; during the displaying of the Nth scan line data stored in the line buffer, storing (N+1)th scan line data in the line buffer; storing the (N+1)th scan line data in the frame buffer; displaying the (N+1)th scan line data stored in the line buffer; repeating the above steps until (N+M)th scan line data stored in the line buffer is displayed; and displaying scan line data stored in the frame buffer from the Nth scan line data to the (N+M)th scan line data.

Abstract: A method for programming and controlling of a plurality of slave devices serially connected in a daisy chain configuration using a master device includes assigning a unique slave address to each slave device in the plurality of slave devices by sending an initialization data packet from the master device serially through the plurality of slave devices; storing, in each of the plurality of slave devices, the assigned slave address; defining a data packet; and transmitting the data packet serially to one or more of the plurality of slave devices. The data packet has a target slave address, a read/write command, a start address, and optionally a register address and an increment value.

Abstract: An LED display panel contains an LED array having a plurality of LED pixels, a plurality of scan switches, and a plurality of LED columns. The anode of each LED pixel in each LED column is connected to a common anode node and the common anode node is connected to an output of a current source, while the cathode of each LED pixel in each LED column is switchably connected to a current sink via one of the plurality of scan switches. The common anode node is connected to a first input of a comparator circuit and is switchably connected to an anode voltage source. The second input of the comparator circuit is connected to a reference voltage source and an output of the comparator circuit signally controls a switch member that switchably connects the common anode node to the current sink.

Abstract: An LED display device includes an LED array and a driver system thereof. The LED display device is configured so that LEDs in the LED array can switch between receiving scan signals at their anodes or receiving scan signals at their cathodes.

Abstract: An LED panel has an interleaved topology in which two adjacent LED rows in the LED panel are driven by different drivers. A delay time can be implemented between starting times two adjacent LED rows. Such an LCD panel can be employed to backlight an LCD panel in an LCD display. Implementing a delay time in driving the LED panel can reduce visual artifacts in the LCD display.

Abstract: A method for programming and controlling of a plurality of slave devices serially connected in a daisy chain configuration using a master device includes assigning a unique slave address to each slave device in the plurality of slave devices by sending an initialization data packet from the master device serially through the plurality of slave devices; storing, in each of the plurality of slave devices, the assigned slave address; defining a data packet; and transmitting the data packet serially to one or more of the plurality of slave devices. The data packet has a target slave address, a read/write command, a start address, and optionally a register address and an increment value.

Abstract: A method for programming and controlling of a plurality of slave devices serially connected in a daisy chain configuration using a master device is disclosed. The method includes broadcasting, from the master device, an initialization data packet to the plurality of slave devices to assign each slave device in the plurality of slave devices a slave address that is unique to said each slave device; storing, in each slave device, the assigned slave address, defining a data packet , wherein the data packet comprises a target slave address, a read/write command, a register address, a increment value, and a start address; and transmitting the data packet serially to one or more of the plurality of slave devices until the target address in the data packet matches the slave address stored in one of the plurality of slave devices.

Abstract: The LED display system includes an array of LEDs and a driver circuit. The driver circuit has a PWM engine, an adder, an accumulator, a multiplier, and a frame butter. The multiplier multiplies an image data of a first bit depth (PWM) with a multiple (M) to produce an input data (PWM_M) having a second bit depth. The multiple has an integer section (MI) of one or more bit in length and a fraction section (MF) of one or more bit in length. The input data has an integer section (PWM_MI) and a fraction section (PWM_MF). The adder adds a value of PWM_MF of a current input data with a value of a remainder in an accumulator. The PWM engine receives PWM data from the frame buffer and generates PWM pulses to drive the LED array.

Abstract: An LED display device includes an LED array and a driver system thereof. The LED display device is configured so that LEDs in the LED array can switch between receiving scan signals at their anodes or receiving scan signals at their cathodes.

Abstract: The LED display system includes an array of LEDs and a driver circuit. The driver circuit has a PWM engine, an adder, an accumulator, a multiplier, and a frame butter. The multiplier multiplies an image data of a first bit depth (PWM) with a multiple (M) to produce an input data (PWM_M) having a second bit depth. The multiple has an integer section (MI) of one or more bit in length and a fraction section (MF) of one or more bit in length. The input data has an integer section (PWM_MI) and a fraction section (PWM_MF). The adder adds a value of PWM_MF of a current input data with a value of a remainder in an accumulator. The PWM engine receives PWM data from the frame buffer and generates PWM pulses to drive the LED array.

Abstract: An LED display system has and LED display panel coupled to a driver circuitry. The driver circuitry includes a scrambled PWM generator, a register, and a memory. The scrambled PWM generator receives an image data from an external source and, after certain compensations, is sent to a scramble PWM generator to be distributed according to a new set of rules that involves a compensation image data K. Image data K can be an empirical value or obtained according a formula using coefficients p and q, which can be obtained by calibration.

Abstract: An LED panel has an interleaved topology in which two adjacent LED rows in the LED panel are driven by different drivers. A delay time can be implemented between starting times two adjacent LED rows. Such an LCD panel can be employed to backlight an LCD panel in an LCD display. Implementing a delay time in driving the LED panel can reduce visual artifacts in the LCD display.

Abstract: An LED display system includes a driver chip and an LED array having m scan lines, n channels, and m scan switches. The driver chip includes an analog circuit and a digital controller that controls the analog circuit. The analog circuit has a plurality of power sources that are electrically connected to the LED array and provide a plurality of driving currents to the n channels of LEDs. Further, the n channels are divided into p groups and each group has q channels, p is an integer of 2 to n. Channels in each of the p groups receive a plurality of PWM signals. The starting times of the input PWM signals to at least two different groups among the p groups are different. Further, PMW signals to the channels in the same group may have a same starting time or may have different starting times.

Abstract: A method for motion blur in an LED display system includes the steps of connecting an LED display panel to a driver circuit; sending, from a transmitter, image data in a plurality of image frames at a predetermined frame rate and a predetermined refresh rate to the driver circuit, wherein each of the plurality of image frames has a frame time period (Tframe) comprising a plurality of refresh time periods (Trefresh); outputting a driving current in the driver circuit to drive the LED display; and turning off the driving current for a period of time (Tinactive). Tinactive bridges two adjacent frame time periods. The value of Tinactive can be determined according to a viewer of persistence of vision or by calibrating the LED display.

Abstract: An LED display system includes a driver chip and an LED array having m scan lines, n channels, and m scan switches. The driver chip includes an analog circuit and a digital controller that controls the analog circuit. The analog circuit has a plurality of power sources that are electrically connected to the LED array and provide a plurality of driving currents to the n channels of LEDs. Further, the n channels are divided into p groups and each group has q channels, p is an integer of 2 to n. Channels in each of the p groups receive a plurality of PWM signals. The starting times of the input PWM signals to at least two different groups among the p groups are different. Further, PMW signals to the channels in the same group may have a same starting time or may have different starting times.

Abstract: A method for generating fractional PWM pulses to drive an light emitting device includes generating multiphase clock signals using a multiphase PLL or DLL includes the steps of generating a plurality of phases of PWM pulses that correspond to a number of phases of the multiphase clock signals, selecting two or more phases amongst the plurality of PWM pulses, performing logic operations of the selected phases of PWM pulses to generate fractional PWM pulses, and generating a driving current using the fractional PWM pulses in a current source. The light emitting device is can be an LED display comprising an LED array having a plurality of channels and a plurality of scan lines. The driving current drives LEDs in one of the plurality of channels.

Abstract: A method for generating fractional PWM pulses to drive an light emitting device includes generating multiphase clock signals using a multiphase PLL or DLL includes the steps of generating a plurality of phases of PWM pulses that correspond to a number of phases of the multiphase clock signals, selecting two or more phases amongst the plurality of PWM pulses, performing logic operations of the selected phases of PWM pulses to generate fractional PWM pulses, and generating a driving current using the fractional PWM pulses in a current source. The light emitting device is can be an LED display comprising an LED array having a plurality of channels and a plurality of scan lines. The driving current drives LEDs in one of the plurality of channels.

Abstract: A method for motion blur in an LED display system includes the steps of connecting an LED display panel to a driver circuit; sending, from a transmitter, image data in a plurality of image frames at a predetermined frame rate and a predetermined refresh rate to the driver circuit, wherein each of the plurality of image frames has a frame time period (Tframe) comprising a plurality of refresh time periods (Trefresh); outputting a driving current in the driver circuit to drive the LED display; and turning off the driving current for a period of time (Tinactive). Tinactive bridges two adjacent frame time periods. The value of Tinactive can be determined according to a viewer of persistence of vision or by calibrating the LED display.

Abstract: An LED display system has and LED display panel coupled to a driver circuitry. The driver circuitry includes a scrambled PWM generator, a register, and a memory. The scrambled PWM generator receives an image data from an external source and, after certain compensations, is sent to a scramble PWM generator to be distributed according to a new set of rules that involves a compensation image data K. Image data K can be an empirical value or obtained according a formula using coefficients p and q, which can be obtained by calibration.

Abstract: An LED display device includes a transmitter having a memory and a pixel mapping table, a plurality of first receivers coupled to the transmitter, a plurality of second receiver modules, and a plurality of LED driver groups. A unique address is assigned to a data packet with a use of the pixel mapping table. The data packet has a set of field information and the set of field information includes the unique address. Each of the second receiver modules is coupled to at least one of the first receivers and includes a plurality of second receivers. None of the plurality of second receivers comprises a pixel mapping memory. Each of the LED driver groups is coupled to one of the plurality of second receivers and includes a plurality of LED drivers.