Micro LED display device
Disclosed is a micro-LED display device configured to prevent unwanted light-emission under all driving conditions regardless of a short circuit between a cathode electrode and an anode electrode of a micro-LED. The micro-LED display device includes a display panel including: a plurality of pixel circuits for driving a plurality of micro-LEDs; and a micro-driver for controlling an operation of each of the plurality of pixel circuits; and a power management circuit configured to manage a level of a bias voltage so that a gap voltage as a difference between a negative voltage and the bias voltage used to selectively drive one of the plurality of micro-LEDs is maintained at a value lower than a threshold voltage of each of the plurality of micro-LEDs.
1 . A micro-LED display device comprising:
a display panel including:
a plurality of pixel circuits configured to drive a plurality of micro-LEDs; and
a micro-driver configured to control an operation of each of the plurality of pixel circuits; and
a power management circuit configured to manage a level of a bias voltage so that a gap voltage as a difference between a negative voltage and the bias voltage used to selectively drive one of the plurality of micro-LEDs is maintained at a value lower than a threshold voltage of each of the plurality of micro-LEDs,
wherein the power management circuit is configured to generate the bias voltage based on a negative feedback voltage fed back from the display panel and a gap setting signal corresponding to the gap voltage.
2 . The micro-LED display device of claim 1 , wherein the power management circuit is configured to generate the negative voltage and provide the generated negative voltage to the display panel.
3 . The micro-LED display device of claim 2 , wherein the power management circuit includes:
a first voltage generation circuit configured to generate the negative voltage based on an input voltage input from an external input power supply and a voltage setting signal; and
a second voltage generation circuit configured to generate the bias voltage based on a reference voltage input from the external input power supply, the gap setting signal, and the negative feedback voltage.
4 . The micro-LED display device of claim 3 , wherein the second voltage generation circuit includes:
a digital-to-analog converter configured to receive the gap setting signal from an external setting unit and to convert the gap setting signal into the gap voltage; and
a computation circuit configured to perform computation on the reference voltage, the gap voltage, and the negative feedback voltage to generate the bias voltage.
5 . The micro-LED display device of claim 1 , wherein the negative voltage is applied to a cathode electrode of a micro-LED from the plurality of micro-LEDs to emit light, the bias voltage is applied to the cathode electrode of a micro-LED from the plurality of micro-LEDs to not emit light, and the bias voltage is higher than the negative voltage.
6 . The micro-LED display device of claim 1 , wherein the display panel includes:
first to 16th row cathode electrodes spaced from each other by a predetermined spacing in a column direction, wherein each of first to 16th row cathode electrodes extends in a row direction of the display panel,
wherein the micro-driver is between a column-directional arrangement of the first to 8th row cathode electrodes and a column-directional arrangement of ninth to 16th row cathode electrodes.
7 . The micro-LED display device of claim 6 , wherein the plurality of pixel circuits are on each of the first to 16th row cathode electrodes and are spaced from each other by a predetermined spacing in a row direction.
8 . The micro-LED display device of claim 7 , wherein the micro-driver is connected to each of the plurality of pixel circuits via a first anode electrode line and a second anode electrode line.
9 . The micro-LED display device of claim 8 , wherein the plurality of pixel circuits include:
first to eighth micro-LEDs connected to the micro-driver via first anode electrode lines, respectively; and
first to eighth redundancy micro-LEDs connected to the micro-driver via second anode electrode lines, respectively.
10 . The micro-LED display device of claim 1 , wherein each of the plurality of pixel circuits includes:
a driving transistor configured to supply a power voltage in response to a gate driving voltage;
a first transistor configured to constitute a current path together with the driving transistor in response to a light-emission signal;
first to eighth micro-LEDs, each having an anode electrode connected to the first transistor; and
a switch circuit configured to selectively connect each of cathode electrodes of the first to eighth micro-LEDs to a power line for the negative voltage or the bias voltage.
11 . The micro-LED display device of claim 10 , wherein the switch circuit includes:
one or more first switches, each of the one or more first switches configured to connect each of the cathode electrodes of the first to eighth micro-LEDs to a power line for the bias voltage; and
one or more second switches, each of the one or more second switches being configured to connect each of the cathode electrodes of the first to eighth micro-LEDs to a power line for the negative voltage.
12 . The micro-LED display device of claim 10 , wherein the switch circuit is configured to apply the negative voltage to the cathode electrode of the micro-LED to emit light and to apply the bias voltage to the cathode electrode of each of remaining micro-LEDs not to emit light.
13 . A micro-LED display device comprising:
a display panel including:
a plurality of pixel circuits for driving a plurality of micro-LEDs; and
a micro-driver configured to control an operation of each of the plurality of pixel circuits,
first to 16th row cathode electrodes extending in a row direction of the display panel and spaced from each by a predefined spacing in a column direction,
wherein the micro-driver between a column-directional arrangement of the first to 8th row cathode electrodes and a column-directional arrangement of the ninth to 16th row cathode electrodes,
further comprising a power management circuit configured to manage a level of a bias voltage so that a gap voltage as a difference between a negative voltage and the bias voltage used to selectively drive one of the plurality of micro-LEDs is maintained at a value lower than a threshold voltage of each of the plurality of micro-LEDs,
wherein the power management circuit is configured to generate the bias voltage based on a negative feedback voltage fed back from the display panel and a gap setting signal corresponding to the gap voltage.
14 . The micro-LED display device of claim 13 , wherein the negative voltage is applied to a cathode electrode of a micro-LED from the plurality of micro-LEDs to emit light, the bias voltage is applied to the cathode electrode of a micro-LED from the plurality of micro-LEDs to not emit light, and the bias voltage is higher than the negative voltage.
15 . The micro-LED display device of claim 14 , wherein the power management circuit is configured to generate the negative voltage and provide the generated negative voltage to the display panel.
16 . The micro-LED display device of claim 15 , wherein the power management circuit includes:
a first voltage generation circuit configured to generate the negative voltage based on an input voltage input from an external input power supply and a voltage setting signal; and
a second voltage generation circuit configured to generate the bias voltage based on a reference voltage input from the external input power supply, the gap setting signal, and the negative feedback voltage.
17 . The micro-LED display device of claim 16 , wherein the second voltage generation circuit includes:
a digital-to-analog converter configured to receive the gap setting signal from an external setting unit and to convert the gap setting signal into the gap voltage; and
a computation circuit configured to perform computation on the reference voltage, the gap voltage, and the negative feedback voltage to generate the bias voltage.
18 . A micro-LED display device comprising:
a display panel including:
a plurality of pixel circuits configured to drive a plurality of micro-LEDs; and
a micro-driver configured to control an operation of each of the plurality of pixel circuits,
wherein each of the plurality of pixel circuits includes:
a driving transistor configured to supply a power voltage in response to a gate driving voltage;
a first transistor configured to constitute a current path together with the driving transistor in response to a light-emission signal;
first to eighth micro-LEDs, each having an anode electrode connected to the first transistor; and
a switch circuit configured to selectively connect each of cathode electrodes of the first to eighth micro-LEDs to a power line for a negative voltage or a bias voltage,
further comprising:
a power management circuit configured to manage a level of the bias voltage so that a gap voltage as a difference between the negative voltage and the bias voltage is maintained at a value lower than a threshold voltage of each of the plurality of micro-LEDs,
wherein the power management circuit is configured to generate the bias voltage based on a negative feedback voltage fed back from the display panel and a gap setting signal corresponding to the gap voltage.
19 . The micro-LED display device of claim 18 , wherein the switch circuit is configured to apply the negative voltage to a cathode electrode of the micro-LED to emit light, and to apply the bias voltage to a cathode electrode of each of remaining micro-LEDs not to emit light.
20 . The micro-LED display device of claim 19 , wherein the switch circuit includes:
one or more first switches, each of the one or more first switches configured to connect each of the cathode electrodes of the first to eighth micro-LEDs to the power line for the bias voltage; and
one or more second switches, each of the one or more second switches configured to connect each of the cathode electrodes of the first to eighth micro-LEDs to the power line for the negative voltage.