Pixel circuit and display panel
View Patent ↗A pixel circuit and a display panel. The pixel circuit includes a driving transistor, a write-in transistor, a first light emission control transistor, a second light emission control transistor, and a first initialization transistor. By initializing a potential of a source or a drain of the driving transistor at least once before and after a charging phase of a frame, the potential of the source or the drain of the driving transistor may be stabilized.
1 . A pixel circuit comprising:
a driving transistor;
a write-in transistor, one of a source or a drain of the write-in transistor being electrically connected to the driving transistor, another of the source or the drain of the write-in transistor being electrically connected to a data line, and a gate of the write-in transistor being connected to a first control line;
a first light emission control transistor, one of a source or a drain of the first light emission control transistor being electrically connected to one of a source or a drain of the driving transistor, another of the source or the drain of the first light emission control transistor being electrically connected to a positive power supply line, and a gate of the first light emission control transistor being electrically connected to a first light emission control line;
a second light emission control transistor, one of a source or a drain of the second light emission control transistor being electrically connected to another of the source or the drain of the driving transistor, another of the source or the drain of the second light emission control transistor being electrically connected to a negative power supply line, and a gate of the second light emission control transistor being electrically connected to the first light emission control line or a second light emission control line; and
a first initialization transistor, one of a source or a drain of the first initialization transistor being electrically connected to the source or the drain of the driving transistor, another of the source or the drain of the first initialization transistor being electrically connected to a first initialization line, and a gate of the first initialization transistor being electrically connected to a second control line and configured to respectively initializing a potential of the source or the drain of the driving transistor at least once before and after a charging phase of a frame;
wherein the pixel circuit further comprises:
a coupling capacitor, one terminal of which being electrically connected to one of the gate of the driving transistor, the source or the drain of the write-in transistor, and another terminal of which being electrically connected to the other of the source or the drain of the second light emission control transistor; and
a storage capacitor, one terminal of which being electrically connected to the other terminal of the coupling capacitor, and another terminal of which being electrically connected to the positive power supply line.
2 . A display panel comprising the pixel circuit of claim 1
wherein a channel type of the driving transistor is the same as a channel type of the write-in transistor, a channel type of the first light emission control transistor, a channel type of the second light emission control transistor, and a channel type of the first initialization transistor.
3 . The display panel of claim 2 , wherein the gate of the second light emission control transistor is electrically connected to the first light emission control line;
during the charging phase, a conduction time of the write-in transistor at least partially overlaps with a conduction time of the first light emission control transistor and/or the second light emission control transistor.
4 . The display panel of claim 3 , wherein the first control line is configured to transmit a first control signal, the second control line is configured to transmit a second control signal, and the first control signal and the second control signal each have a first pulse and a second pulse successively distributed in a frame;
a waveform of the first control signal is the same as a waveform of the second control signal, and a phase of the second control signal lags behind a phase of the first control signal;
within a frame, the first pulse of the second control signal is temporally located between the first pulse of the first control signal and the second pulse of the first control signal, and the second pulse of the first control signal is temporally located between the first pulse of the second control signal and the second pulse of the second control signal.
5 . The display panel of claim 4 , wherein the data line is configured to transmit a data signal; a duration of the first pulse is less than a duration of the second pulse;
within the duration of the first pulse, a potential of the data signal is less than a pulse amplitude of the data signal.
6 . The display panel of claim 2 , wherein the pixel circuit further comprises:
a light emitting device whose anode is electrically connected to the other of the source or the drain of the second light emitting control transistor, and whose cathode is connected to the negative power supply line; and
a second initialization transistor, one of a source or a drain of the second initialization transistor being connected to the anode of the light emitting device, another of the source or the drain of the second initialization transistor being electrically connected to a second initialization line, and a gate of the second initialization transistor being electrically connected to a fourth control line or the third control line;
wherein the second initialization transistor is in a conductive state a plurality of times during a non-luminous phase of a frame.
7 . The display panel of claim 6 , wherein a channel aspect ratio of the second light emission control transistor, the first initialization transistor, and the second initialization transistor is in a range of 0.5˜1.
8 . The display panel of claim 2 , wherein under a condition that the first initialization transistor is in a conductive state, the driving transistor is in the conductive state, and the write-in transistor, the first light emission control transistor, and the second light emission control transistor are all in a cutoff state.
9 . The display panel of claim 2 , wherein at least one of the driving transistor, the write-in transistor, the first light emission control transistor, the second light emission control transistor, and the first initialization transistor is an N-channel metal oxide thin film transistor.
10 . The pixel circuit of claim 1 , wherein the gate of the second light emission control transistor is electrically connected to the first light emission control line;
during the charging phase, a conduction time of the write-in transistor at least partially overlaps with a conduction time of the first light emission control transistor and/or the second light emission control transistor.
11 . The pixel circuit of claim 10 , wherein the first control line is configured to transmit a first control signal, the second control line is configured to transmit a second control signal, and the first control signal and the second control signal each have a first pulse and a second pulse successively distributed in a frame;
a waveform of the first control signal is the same as a waveform of the second control signal, and a phase of the second control signal lags behind a phase of the first control signal;
within a frame, the first pulse of the second control signal is temporally located between the first pulse of the first control signal and the second pulse of the first control signal, and the second pulse of the first control signal is temporally located between the first pulse of the second control signal and the second pulse of the second control signal.
12 . The pixel circuit of claim 11 , wherein the data line is configured to transmit a data signal; a duration of the first pulse is less than a duration of the second pulse;
within the duration of the first pulse, a potential of the data signal is less than a pulse amplitude of the data signal.
13 . The pixel circuit of claim 1 , wherein under a condition that the first initialization transistor is in a conductive state, the driving transistor is in the conductive state, and the write-in transistor, the first light emission control transistor, and the second light emission control transistor are all in a cutoff state.
14 . The pixel circuit of claim 1 , wherein the pixel circuit further comprises:
a light emitting device whose anode is electrically connected to the other of the source or the drain of the second light emitting control transistor, and whose cathode is connected to the negative power supply line; and
a second initialization transistor, one of a source or a drain of the second initialization transistor being connected to the anode of the light emitting device, another of the source or the drain of the second initialization transistor being electrically connected to a second initialization line, and a gate of the second initialization transistor being electrically connected to a fourth control line or the third control line;
wherein the second initialization transistor is in a conductive state a plurality of times during a non-luminous phase of a frame.
15 . A pixel circuit comprising:
a driving transistor;
a write-in transistor, one of a source or a drain of the write-in transistor being electrically connected to the driving transistor, another of the source or the drain of the write-in transistor being electrically connected to a data line, and a gate of the write-in transistor being connected to a first control line;
a first light emission control transistor, one of a source or a drain of the first light emission control transistor being electrically connected to one of a source or a drain of the driving transistor, another of the source or the drain of the first light emission control transistor being electrically connected to a positive power supply line, and a gate of the first light emission control transistor being electrically connected to a first light emission control line;
a second light emission control transistor, one of a source or a drain of the second light emission control transistor being electrically connected to another of the source or the drain of the driving transistor, another of the source or the drain of the second light emission control transistor being electrically connected to a negative power supply line, and a gate of the second light emission control transistor being electrically connected to the first light emission control line or a second light emission control line; and
a first initialization transistor, one of a source or a drain of the first initialization transistor being electrically connected to the source or the drain of the driving transistor, another of the source or the drain of the first initialization transistor being electrically connected to a first initialization line, and a gate of the first initialization transistor being electrically connected to a second control line and configured to respectively initializing a potential of the source or the drain of the driving transistor at least once before and after a charging phase of a frame;
wherein the pixel circuit further comprises:
a storage capacitor, one terminal of which being electrically connected to the gate of the driving transistor, and another end of which being electrically connected to the other of the source and the drain of the second light emission control transistor; and
a first transistor, one of a source or a drain of the first transistor being electrically connected to one of the source or the drain of the driving transistor, another of the source or the drain of the first transistor being electrically connected to the gate of the driving transistor, and a gate of the first transistor being electrically connected to a third control line;
wherein one of the source or the drain of the write-in transistor is electrically connected to another of the source or the drain of the driving transistor; under a condition that the first initialization transistor is in a conductive state, the driving transistor is in the conductive state, and the write-in transistor, the first light emission control transistor, the second light emission control transistor, and the first transistor are all in a cutoff state.
16 . A display panel comprising the pixel circuit of claim 15 , wherein a channel type of the driving transistor is the same as a channel type of the write-in transistor, a channel type of the first light emission control transistor, a channel type of the second light emission control transistor, and a channel type of the first initialization transistor.
17 . The display panel of claim 16 , wherein under a condition that the first initialization transistor is in a cutoff state, both the first transistor and the first light emission control transistor are in a conductive state, and both the write-in transistor and the second light emission control transistor are in a cutoff state.
18 . The pixel circuit of claim 15 , wherein under a condition that the first initialization transistor is in a cutoff state, both the first transistor and the first light emission control transistor are in a conductive state, and both the write-in transistor and the second light emission control transistor are in a cutoff state.