PIXEL CIRCUITS FOR LIGHT EMITTING ELEMENTS
Embodiments of pixel circuits for light emitting elements are disclosed herein. In one example, a pixel circuit includes a pixel driver and a bridge transistor. The pixel driver is configured to receive a data signal and drive a light emitting element based on the data signal. The bridge transistor includes a gate terminal receiving a first bias signal, a source terminal coupled to the pixel driver, a drain terminal coupled to a terminal of the light emitting element, and a body terminal coupled to the source terminal or receiving the data signal. The first bias signal controls a voltage at the source terminal.
1 . A pixel circuit, comprising:
a pixel driver configured to receive a data signal and drive a light emitting element based on the data signal; and
a bridge transistor comprising a gate terminal receiving a first bias signal, a source terminal coupled to the pixel driver, a drain terminal coupled to a terminal of the light emitting element, and a body terminal coupled to the source terminal or receiving the data signal,
wherein the first bias signal controls a voltage at the source terminal.
2 . The pixel circuit of claim 1 , wherein the pixel driver comprises:
a driving transistor comprising a source terminal or a drain terminal coupled to the source terminal of the bridge transistor, a body terminal receiving second bias signal, and a gate terminal;
a capacitor comprising a terminal coupled to the gate terminal of the driving transistor; and
a switch configured to, in response to a scan signal, charge the capacitor to a voltage based on the data signal, so that the gate terminal of the driving transistor is biased based on the voltage charged to the capacitor.
3 . The pixel circuit of claim 1 , wherein the first bias signal controls the voltage at the source terminal to be a midpoint voltage when the light emitting element is turned off.
4 . The pixel circuit of claim 1 , wherein the bridge transistor is a p-type transistor, and the terminal of the light emitting element is an anode.
5 . The pixel circuit of claim 1 , wherein the bridge transistor is a n-type transistor, and the terminal of the light emitting element is a cathode.
6 . The pixel circuit of claim 2 , wherein a voltage of the first bias signal is the same as a voltage of the second bias signal.
7 . The pixel circuit of claim 1 , wherein the light emitting element is an organic light emitting diode (OLED) or a micro-LED.
8 . A circuit for driving a plurality of light emitting elements, comprising:
a plurality of pixel circuits, each of the plurality of pixel circuits configured to drive one of a plurality of light emitting elements arranged in a same row and comprising:
a pixel driver configured to receive a data signal and drive the corresponding light emitting element based on the data signal; and
a bridge transistor comprising a gate terminal receiving a same first bias signal, a source terminal coupled to the pixel driver, a drain terminal coupled to a terminal of the light emitting element, and a body terminal coupled to the source terminal or receiving the data signal, wherein the first bias signal controls a voltage at the source terminal; and
a discharge controller coupled to the pixel drivers of each of the plurality of pixel circuits and configured to, in response to a global discharge signal, simultaneously control discharge of the plurality of light emitting elements in the same row.
9 . The circuit of claim 8 , further comprising:
a light emission controller coupled to a power source and the pixel drivers of each of the plurality of pixel circuits and configured to, in response to a global light emission signal, simultaneously control light emission of the plurality of light emitting elements in the same row.
10 . The circuit of claim 9 , wherein each of the plurality of pixel drivers comprises:
a driving transistor comprising a source terminal or a drain terminal coupled to the source terminal of the bridge transistor or the discharge controller and the light emission controller, a body terminal receiving a second bias signal, and a gate terminal;
a capacitor comprising a terminal coupled to the gate terminal of the driving transistor; and
a switch configured to, in response to a scan signal, charge the capacitor to a voltage based on the data signal, so that the gate terminal of the driving transistor is biased based on the voltage charged to the capacitor.
11 . The circuit of claim 10 , wherein the switches of each of the plurality of pixel drivers receive the same scan signal.
12 . The circuit of claim 8 , wherein the discharge controller is configured to simultaneously control discharge of the plurality of light emitting elements to a voltage of the first bias signal.
13 . The circuit of claim 8 , wherein the bridge transistor is a p-type transistor, and the terminal of the light emitting element is an anode.
14 . The circuit of claim 8 , wherein the bridge transistor is a n-type transistor, and the terminal of the light emitting element is a cathode.
15 . A circuit for driving a plurality of light emitting elements, comprising:
a plurality of pixel circuits, each of the plurality of pixel circuits configured to drive one of a plurality of light emitting elements arranged in a same row and comprising a pixel driver configured to receive a data signal and drive the corresponding light emitting element based on the data signal;
a discharge controller coupled to the pixel drivers of each of the plurality of pixel circuits and configured to, in response to a global discharge signal, simultaneously control discharge of the plurality of light emitting elements in the same row; and
a light emission controller coupled to a power source and the pixel drivers of each of the plurality of pixel circuits and configured to, in response to a global light emission signal, simultaneously control light emission of the plurality of light emitting elements in the same row.
16 . The circuit of claim 15 , wherein each of the plurality of pixel circuits further comprises:
a bridge transistor comprising a gate terminal receiving a first bias signal, a source terminal coupled to the corresponding pixel driver, a drain terminal coupled to a terminal of the corresponding light emitting element, and a body terminal coupled to the source terminal or receiving the data signal,
wherein the first bias signal controls a voltage at the source terminal.
17 . The circuit of claim 15 , wherein each of the plurality of pixel drivers comprises:
a driving transistor comprising a source terminal or a drain terminal coupled to the source terminal of the bridge transistor or the discharge controller and the light emission controller, a body terminal receiving a second bias signal, and a gate terminal;
a capacitor comprising a terminal coupled to the gate terminal of the driving transistor; and
a switch configured to, in response to a scan signal, charge the capacitor to a voltage based on the data signal, so that the gate terminal of the driving transistor is biased based on the voltage charged to the capacitor.
18 . The circuit of claim 17 , wherein the switches of each of the plurality of pixel drivers receive the same scan signal.
19 . The circuit of claim 16 , wherein the bridge transistor is a p-type transistor, and the terminal of the light emitting element is an anode.
20 . The circuit of claim 16 , wherein the bridge transistor is a n-type transistor, and the terminal of the light emitting element is a cathode.