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US 12,701,863 B2Granted
Display panel, pixel driving circuits, and display device
AssigneeWuhan China Star Optoelectronics Technology Co., Ltd.
InventorsHong Cheng, Yanqing Guan, Chao Tian, Fei Ai, Guanghui Liu
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Abstract
A display panel, a pixel driving circuit, and a display device are provided. Driving transistors include a first transistor and a second transistor connected in parallel. An absolute value of a threshold voltage of the first transistor is greater than an absolute value of a threshold voltage of the second transistor. A carrier mobility of the first transistor is greater than a carrier mobility of the second transistor. A driving current is affected by characteristics of the second transistor and an increase speed is slowed down, which improves a problem of color unevenness of the display panel at low brightness.
Claims20
A display panel, comprising:
- a plurality of light-emitting devices;
- and
- a plurality of pixel driving circuits, wherein each of the pixel driving circuits is electrically connected to at least one of the light-emitting devices, each of the pixel driving circuits comprises driving transistors, the driving transistors and a corresponding light-emitting device are connected in series between a first voltage terminal and a second voltage terminal, and the driving transistors comprise a first transistor and a second transistor connected in parallel;
- and
- wherein an absolute value of a threshold voltage of the first transistor is greater than an absolute value of a threshold voltage of the second transistor, and a carrier mobility of the first transistor is greater than a carrier mobility of the second transistor;
- wherein the display panel further comprises:
- a first semiconductor layer comprising an active layer of the first transistor;
- a second semiconductor layer comprising an active layer of the second transistor;
- a first metal layer;
- and
- a second metal layer;
- wherein an orthographic projection of the active layer of the second transistor on the active layer of the first transistor overlaps the active layer of the first transistor;
- wherein the first metal layer comprises a gate of the first transistor, the gate of the first transistor and the active layer of the first transistor at least partially overlap;
- the second metal layer comprises a gate of the second transistor, the gate of the second transistor and the active layer of the second transistor at least partially overlap, and an orthographic projection of the gate of the second transistor on the first metal layer overlaps the gate of the first transistor.
11 more elements
A pixel driving circuit, comprising:
- driving transistors, wherein the driving transistors comprise a first transistor and a second transistor connected in parallel;
- and
- a light-emitting device connected in series with the driving transistors between a first voltage terminal and a second voltage terminal;
- wherein an absolute value of a threshold voltage of the first transistor is greater than an absolute value of a threshold voltage of the second transistor, the first transistor comprises a silicon semiconductor layer, and the second transistor comprises an oxide semiconductor layer;
- wherein an orthographic projection of an active layer of the second transistor on an active layer of the first transistor overlaps the active layer of the first transistor;
- wherein a gate of the first transistor and the active layer of the first transistor at least partially overlap;
- wherein a gate of the second transistor and the active layer of the second transistor at least partially overlap, and an orthographic projection of the gate of the second transistor on the gate of the first transistor overlaps the gate of the first transistor.
4 more elements
A display device, comprising a display panel, wherein the display panel comprises:
- a plurality of light-emitting devices;
- and
- a plurality of pixel driving circuits, wherein each of the pixel driving circuits is electrically connected to at least one of the light-emitting devices, each of the pixel driving circuits comprises driving transistors, the driving transistors and a corresponding light-emitting device are connected in series between a first voltage terminal and a second voltage terminal, and the driving transistors comprise a first transistor and a second transistor connected in parallel;
- and
- wherein an absolute value of a threshold voltage of the first transistor is greater than an absolute value of a threshold voltage of the second transistor, and a carrier mobility of the first transistor is greater than a carrier mobility of the second transistor;
- wherein the display panel further comprises:
- a first semiconductor layer comprising an active layer of the first transistor;
- a second semiconductor layer and comprising an active layer of the second transistor;
- a first metal layer;
- and
- a second metal layer;
- wherein an orthographic projection of the active layer of the second transistor on the active layer of the first transistor overlaps the active layer of the first transistor;
- wherein the first metal layer comprises a gate of the first transistor, the gate of the first transistor and the active layer of the first transistor at least partially overlap;
- the second metal layer comprises a gate of the second transistor, the gate of the second transistor and the active layer of the second transistor at least partially overlap, and an orthographic projection of the gate of the second transistor on the first metal layer overlaps the gate of the first transistor.
11 more elements
Dependencies are inferred from the claim text.