Abstract: The present invention discloses a light emitting device array billboard and a control method thereof. The light emitting device array billboard includes a light emitting device array circuit, plural line switch circuits, plural channel switch circuits, plural ghost image compensation switch circuits, and a control circuit. The control circuit operates the line switch circuits and the channel switch circuit to turn ON a selected light emitting device for a duty period in a lighting period, and operates the plural ghost image compensation switch circuits to electrically connect a channel node corresponding to the selected light emitting device to a ghost image compensation voltage after the lighting period. The control circuit further adjusts a channel operation signal according to a gray scale compensation signal, to turn ON the selected light emitting device for a gray scale compensation period in addition to the duty period.

Abstract: The present invention discloses a light emitting device control circuit and a control method thereof, for controlling a light emitting device array display. The present invention controls not only the conduction timing and duration of one or more selected light emitting devices in the light emitting device array display, but also controls the current flowing through the selected light emitting devices by a variable current source, such that in one frame of a given length, the resolution of the brightness of the light emitting devices is increased.

Abstract: The present invention discloses a light emitting device array billboard and a control method thereof. The light emitting device array billboard includes a light emitting device array circuit, plural line switch circuits, plural channel switch circuits, plural ghost image compensation switch circuits, and a control circuit. The control circuit operates the line switch circuits and the channel switch circuit to turn ON a selected light emitting device for a duty period in a lighting period, and operates the plural ghost image compensation switch circuits to electrically connect a channel node corresponding to the selected light emitting device to a ghost image compensation voltage after the lighting period. The control circuit further adjusts a channel operation signal according to a gray scale compensation signal, to turn ON the selected light emitting device for a gray scale compensation period in addition to the duty period.

Abstract: A LED driver using a PWM signal for dimming control includes a power converter and a current regulator. The power converter provides an output voltage and a load current for a plurality of LEDs. The current regulator provides a load current dependent signal for the power converter to speed up load transient response caused by variation of the load current, to reduce the ripple of the output voltage, and thereby to avoid audio noise during PWM dimming.

Abstract: The invention provides a current control circuit and a current control method. The current control circuit controls a current supplied to a current-controlled device according to a conduction control signal. The current control circuit includes: a conduction control switch coupled to the current-controlled device, for determining whether to conduct the current according to the conduction control signal; and a plurality of current control switches connected to one another in series and coupled to the conduction control switch, for controlling a magnitude of the current.

Abstract: The present invention discloses a light emitting device array billboard and a row switch circuit and a control method thereof. The light emitting device array billboard includes a light emitting device array circuit, plural row switch circuits, plural column driver circuits, and a control circuit. The light emitting device array circuit includes plural light emitting devices arranged by columns and rows. Each row switch circuit determines whether to electrically connect a row conduction voltage to the corresponding row node or to discharge charges at the corresponding row node through a discharging path according to a row selection signal. Each column driver circuit determines whether or not to electrically connect a column conduction voltage to the corresponding column node according to a column selection signal. The control circuit provides the row selection signal and the column selection signal to the row switch circuits and the column driver circuits.

Abstract: A LED driver using a PWM signal for dimming control includes a power converter and a current regulator. The power converter provides an output voltage and a load current for a plurality of LEDs. The current regulator provides a load current dependent signal for the power converter to speed up load transient response caused by variation of the load current, to reduce the ripple of the output voltage, and thereby to avoid audio noise during PWM dimming.

Abstract: The present invention provides a transistor switch on a light emitting device channel, the transistor switch receiving a control voltage VG. A current source circuit controls the current on the light emitting device channel, the current source circuit requiring a minimum voltage VR for normal operation. The present invention further provides a dynamic headroom controller circuit which compares a voltage VS at a current outflow end of the transistor switch with the voltage VR to determine the relationship between the voltage VS and the voltage VR when the control voltage VG is higher than a reference voltage VH, and adjusts the voltage difference between the voltage VS and the voltage VR accordingly.

Abstract: A boost converter includes a load disconnect switch connected between a voltage input terminal and an inductor, a power switch connected to the inductor by a switching node, a diode connected between the switching node and a voltage output terminal, and an output capacitor connected to the voltage output terminal to provide an output voltage. A protection apparatus is connected to the load disconnect switch, switching node and power switch to monitor the voltage at the switching node and the output voltage to provide open circuit and short circuit protection for the boost converter.

Abstract: The present invention discloses an LED array control circuit with voltage adjustment function and a driver circuit and a method for the same. The LED array includes multiple LED strings each of which has multiple LED devices connected in series. The LED array control circuit includes: a power supply circuit for providing a supply voltage to the LED array; and an LED driver circuit for controlling current through each LED string, the LED driver circuit including: multiple current sources corresponding to the multiple LED strings respectively, each current source having a first end which is coupled to a corresponding LED string, and a second end; and a voltage adjustment circuit for adjusting a voltage of the second end of a corresponding current source according to a signal indicating a voltage drop across the corresponding LED string.

Abstract: A method for driving a display includes following steps. A display panel is divided into a plurality of bright regions and a plurality of dark regions, wherein the dark regions and the bright regions are alternately arranged so that the bright regions within the display panel are not adjacent to each other. Next, a full-color frame is divided into four sub-frames, wherein the sub-frames are matched with the four color-orders one by one. In this way, the display randomly displays the sub-frames in a frame period.

Abstract: A method for driving a display is provided. According to the driving method, a display panel is divided into a plurality of bright regions and a plurality of dark regions, wherein the dark regions and the bright regions are alternately arranged so that the bright regions within the display panel are not adjacent to each other. Next, a full-color frame is divided into four sub-frames, wherein the sub-frames are matched with the four color-orders one by one. In this way, the display randomly displays the sub-frames in a frame period.

Abstract: A method for driving a display is provided. According to the driving method, a display panel is divided into a plurality of bright regions and a plurality of dark regions, wherein the dark regions and the bright regions are alternately arranged so that the bright regions within the display panel are not adjacent to each other. Next, a full-color frame is divided into four sub-frames, wherein the sub-frames are matched with the four color-orders one by one. In this way, the display randomly displays the sub-frames in a frame period.

Abstract: A LED display system includes multiple LEDs, a power converter to produce a supply voltage for the LEDs, and multiple drivers to drive the LEDs. According to the maximum one of the forward voltages of the LEDs, the drivers provides a feedback signal for the supply voltage control, and the feedback signal is amplified or digitized to reduce the voltage drop in the global power line.

Abstract: The present invention discloses an LED array control circuit with voltage adjustment function and a driver circuit and a method for the same. The LED array includes multiple LED strings each of which has multiple LED devices connected in series. The LED array control circuit includes: a power supply circuit for providing a supply voltage to the LED array; and an LED driver circuit for controlling current through each LED string, the LED driver circuit including: multiple current sources corresponding to the multiple LED strings respectively, each current source having a first end which is coupled to a corresponding LED string, and a second end; and a voltage adjustment circuit for adjusting a voltage of the second end of a corresponding current source according to a signal indicating a voltage drop across the corresponding LED string.

Abstract: The present invention provides a transistor switch on a light emitting device channel, the transistor switch receiving a control voltage VG. A current source circuit controls the current on the light emitting device channel, the current source circuit requiring a minimum voltage VR for normal operation. The present invention further provides a dynamic headroom controller circuit which compares a voltage VS at a current outflow end of the transistor switch with the voltage VR to determine the relationship between the voltage VS and the voltage VR when the control voltage VG is higher than a reference voltage VH, and adjusts the voltage difference between the voltage VS and the voltage VR accordingly.

Abstract: A boost converter includes a load disconnect switch connected between a voltage input terminal and an inductor, a power switch connected to the inductor by a switching node, a diode connected between the switching node and a voltage output terminal, and an output capacitor connected to the voltage output terminal to provide an output voltage. A protection apparatus is connected to the load disconnect switch, switching node and power switch to monitor the voltage at the switching node and the output voltage to provide open circuit and short circuit protection for the boost converter.

Abstract: A LED display system includes multiple LEDs, a power converter to produce a supply voltage for the LEDs, and multiple drivers to drive the LEDs. According to the maximum one of the forward voltages of the LEDs, the drivers provides a feedback signal for the supply voltage control, and the feedback signal is amplified or digitized to reduce the voltage drop in the global power line.

Abstract: A method for driving a display is disclosed. According to the driving method, a display panel is divided into a plurality of bright regions and a plurality of dark regions, wherein the dark regions and the bright regions are alternately arranged so that the bright regions within the display panel are not adjacent to each other. Next, a full-color frame is divided into four sub-frames, wherein the sub-frames are matched with the four color-orders one by one. In this way, the display randomly displays the sub-frames in a frame period.