TWI892789B - Display system - Google Patents

Abstract

A display system includes a display panel divided into a plurality of display blocks arranged in rows and columns, each display block including a plurality of micro-light-emitting diodes (microLEDs) driven by a corresponding driver disposed in a corresponding display block; a power management unit (PMU) that dynamically provides different power-supply voltages for the drivers respectively during a line scan period or a frame scan period; and a timing controller that determines the different power-supply voltages for the PMU according to content of data to be display on the display panel.

Description

Display system

The present invention relates to a display system, and more particularly to power management of the display system.

MicroLED (microLED, mLED, or μLED) displays are a type of flat panel display composed of individual microscopic LEDs ranging in size from 1 to 100 microns. Compared to traditional liquid crystal display panels, microLED displays offer higher contrast and faster response times while consuming less power. While microLEDs share the low power consumption characteristics of organic light-emitting diodes (OLEDs), microLEDs utilize Group III-V diode technology (such as gallium nitride), resulting in higher brightness, higher luminous efficacy, and a longer lifespan than organic light-emitting diodes.

Conventional micro-LED display systems may use a pulse width modulation (PWM) mechanism to generate a pulse width modulated signal whose duty cycle is proportional to the brightness (or intensity) of the data provided to the micro-LED display panel.

Traditional micro-LED display systems, regardless of whether they use pulse width modulation (PWM) mechanisms, provide a fixed power supply to a fluctuating load, resulting in low power efficiency.

Therefore, there is an urgent need to propose a novel mechanism to overcome the many shortcomings of traditional micro-luminescent diode display systems.

In view of the above, one of the objectives of the embodiments of the present invention is to provide a display system that can dynamically provide different power supply voltages to the driver, thereby effectively improving the overall power performance of the display panel.

According to an embodiment of the present invention, a display system includes a display panel, a power management unit, and a timing controller. The display panel is divided into a plurality of display blocks arranged in rows and columns. Each display block includes a plurality of micro-LEDs, driven by corresponding drivers, located in the corresponding display block. The power management unit dynamically provides different power supply voltages to the plurality of drivers during line scans or frame scans. The timing controller determines different power supply voltages for the power management unit based on the data content to be displayed on the display panel.

FIG1 shows a schematic diagram of a display panel 10 according to an embodiment of the present invention, which can be divided into a plurality of display blocks 11 arranged in rows and columns. Each display block 11 includes a plurality of microLEDs driven by corresponding drivers 12 disposed within the corresponding display block 11.

FIG2 shows a block diagram of a display system 100 according to an embodiment of the present invention. Driver 12 may include a first circuit 121 that turns on at least one row of micro-LEDs 13 by scanning lines 1211 at a time. Driver 12 may include a second circuit 122 that provides a (pulse-width modulated) data signal to the turned-on row of micro-LEDs 13 via a data line 1221 (or channel). It is worth noting that the duty cycle of the pulse-width modulated data signal is proportional to the brightness of the data provided to the display panel 10.

FIG3 illustrates a timing diagram of the data signals of the display system 100 in FIG2. Here, the (horizontal) line scan signal HDE defines a line scan period for scanning a (turned-on) row of micro-LEDs 13. As shown in the figure, the data signals for the odd-numbered data lines (D1, D3, D5, D7, ...) are provided at the beginning of the line scan period, while the data signals for the even-numbered data lines (D2, D4, D6, D8, ...) are provided at the end of the line scan period. Therefore, the data lines do not provide data signals simultaneously, thus avoiding the problem of peak power consumption at the beginning of the line scan period.

Figures 4A and 4B are block diagrams of a display system 100 according to an embodiment of the present invention. In this embodiment, the drivers 12 (of the display panel 10) can be grouped (for example, three drivers 12 per group, as shown in Figures 4A and 4B). It is worth noting that, considering the ground impedance, each group of drivers 12 can be grounded separately (as shown in Figure 4A), or all drivers 12 can be grounded together (as shown in Figure 4B).

According to one feature of this embodiment, the display system 100 may include a power management unit 15, which may include a power generator 151 for dynamically generating and providing a plurality of different power supply voltages AVDD1-AVDDn to each set of drivers 12 during a line scan period (for scanning a line) or a frame scan period (for scanning a frame).

In this embodiment, the display system 100 may include a timing controller 14. During a line scan or frame scan period, the timing controller 14 may modulate the duty cycle of the data signal (i.e., the data content) based on the pulse width to determine the total current required by the corresponding set of drivers 12. Based on the total current required by the corresponding set of drivers 12 during the line scan or frame scan period, the timing controller 14 may determine the power supply voltage AVDDx (x = 1 to n), ensuring that the minimum power supply voltage is sufficient to provide the total current required by the corresponding set of drivers 12. The determined power supply voltage AVDDx is then fed to the power management unit 15 to generate the power supply voltages AVDD1 to AVDDn. Thereby, the overall power efficiency of the display panel 10 can be effectively improved.

FIG5 shows a simplified circuit diagram of series impedances to form a total equivalent impedance. The series impedance may include: (1) the impedance R_A of an external conductor (e.g., located on a printed circuit board) between the power input pad of the driver 12 and the power output pad of the power management unit 15 (which is used to provide the power supply voltage AVDD); (2) the equivalent internal impedance R_mosA associated with the power input pad of the driver 12; (3) the equivalent internal impedance R_mosB associated with the common power pad of the driver 12; and (4) the impedance R_GND of an external conductor (e.g., located on a printed circuit board) between the common power pad of the driver 12 and the common voltage node VCOM.

Multiplying the total current determined above by the total equivalent impedance and adding the voltage drop across the micro-LEDs 13 yields the power supply voltage AVDD for the corresponding set of drivers 12 during line scans or frame scans, which can be expressed as follows: AVDD = Vd + I_total x (R_A + R_mosA + R_mosB + R_GND) Where Vd represents the voltage drop across the micro-LEDs 13, and I_total represents the total current required by the corresponding set of drivers 12.

According to the above embodiment, since the data signal is pulse-width modulated according to the brightness of the corresponding data, the brightness of the data (i.e., the data content) affects the total current I_total, which in turn affects the power supply voltage AVDD. Thus, by appropriately adjusting the power supply voltage AVDD based on the data content, the overall power efficiency of the display panel 10 can be effectively improved.

The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the patent application of the present invention. Any other equivalent changes or modifications that do not deviate from the spirit disclosed in the invention should be included in the scope of the patent application below.

100: Display system 10: Display panel 11: Display block 12: Driver 121: First circuit 1211: Scan line 122: Second circuit 1221: Data line 13: Micro-LED 14: Timing controller 15: Power management unit 151: Power generator HDE: Line scan signal D1-D8: Data lines AVDD: Power supply voltage AVDD1-AVDDn: Power supply voltage VCOM: Common voltage node R_A: External wiring impedance R_mosA: Equivalent internal impedance R_mosB: Equivalent internal impedance R_GND: External wiring impedance

Figure 1 shows a schematic diagram of a display panel according to an embodiment of the present invention, which can be divided into a plurality of display blocks arranged in rows and columns. Figure 2 shows a block diagram of a display system according to an embodiment of the present invention. Figure 3 shows a timing diagram of data signals in the display system shown in Figure 2. Figures 4A and 4B show block diagrams of a display system according to an embodiment of the present invention. Figure 5 shows a simplified circuit diagram of connecting impedances in series to form a total equivalent impedance.

100: Display system

12:Driver

14: Timing Controller

15: Power Management Unit

151: Power Generator

AVDD1~AVDDn: Power supply voltage

Claims (11)

A display system comprises: A display panel divided into a plurality of display blocks arranged in rows and columns, each display block comprising a plurality of micro-luminescent diodes driven by corresponding drivers disposed in the corresponding display block; A power management unit dynamically provides different power supply voltages to the plurality of drivers during a line scan period or a frame scan period; and A timing controller determines the different power supply voltages to be supplied to the power management unit based on the data content to be displayed on the display panel. The timing controller determines the power supply voltage to the corresponding display block based on the current required by the driver of the corresponding display block during a line scan period or a frame scan period. The display system of claim 1, wherein the power management unit comprises: A power generator for generating the different power supply voltages. The display system of claim 1, wherein the drivers of the display panel are divided into multiple groups. A display system as claimed in claim 3, wherein the power supply voltage is determined based on the total current required by the corresponding group of drivers during a line scan period or a frame scan period, so that the minimum power supply voltage is sufficient to provide the total current required by the corresponding group of drivers. The display system of claim 4, wherein the timing controller modulates the duty cycle of the data signal according to the pulse width during a line scan period or a frame scan period to determine the total current required by the corresponding set of drivers. The display system of claim 5, wherein the power supply voltage is obtained by multiplying the required total current by the total equivalent impedance and adding the voltage drop of the micro-luminescent diode. The system of claim 6, wherein the total equivalent impedance includes the following impedances connected in series: An impedance of an external wire between a power input pad of the driver and a power output pad of the power management unit, the power output pad being used to provide a power supply voltage; An equivalent internal impedance associated with the power input pad of the driver; An equivalent internal impedance associated with a common power pad of the driver; and An impedance of an external wire between the common power pad of the driver and a common node. The display system of claim 4, wherein the timing controller determines the total current required by the corresponding set of drivers based on the data signal during a line scan period or a frame scan period, and determines the power supply voltage of the corresponding set of drivers based on the determined total current. The display system of claim 3, wherein each set of drivers is grounded separately. The display system of claim 3, wherein each set of drivers is commonly grounded. The display system of claim 1, wherein the driver comprises: a first circuit for turning on at least one row of micro-luminescent diodes at a time; and a second circuit for providing a pulse-width modulated data signal to the turned-on row of micro-luminescent diodes; wherein the duty cycle of each pulse-width modulated data signal is proportional to the brightness of the data provided to the display panel.