Display device
View Patent ↗Embodiments of the present invention relate to a display device. In an embodiment, the display device includes a scanning signal line for transferring a scanning signal, a data line crossing the scanning signal line and transferring a data voltage, a switching transistor connected to the scanning signal line and the data line, a driving transistor connected to the switching transistor, a first transistor connected between the driving transistor and a driving voltage terminal, and a light-emitting element connected between the driving transistor and a common voltage terminal. The first transistor operates in a saturation region, and the driving transistor operates in a linear region. In this way, display characteristics may be improved by reducing deviation of a driving current due to deviation of characteristics of a driving transistor or a driving voltage.
1. A display device comprising:
a scanning signal line for transferring a scanning signal;
a data line crossing the scanning signal line and transferring a data voltage;
a switching transistor connected to the scanning signal line and the data line;
a driving transistor connected to the switching transistor;
a first transistor connected between the driving transistor and a driving voltage terminal; and
a light-emitting element connected between the driving transistor and a common voltage terminal,
wherein the first transistor operates in a saturation region when receiving a driving voltage from the driving voltage terminal, and
the driving transistor operates in a linear region when the first transistor operates in the saturation region.
2. The display device of claim 1 , wherein the first transistor has a channel type identical to a channel type of the driving transistor.
3. The display device of claim 2 , wherein the first transistor and the driving transistor are n-channel MOS field effect transistors.
4. The display device of claim 3 , wherein a control terminal of the first transistor is connected to a first voltage terminal, and
a control terminal of the driving transistor is connected to an output terminal of the switching transistor.
5. The display device of claim 3 , wherein a control terminal of the first transistor and a control terminal of the driving transistor are connected to an output terminal of the switching transistor.
6. The display device of claim 5 , wherein a ratio of a channel width to a channel length of the driving transistor is smaller than a ratio of a channel width to a channel length of the first transistor.
7. The display device of claim 1 , further comprising a storage capacitor connected between the switching transistor and the first transistor.
8. The display device of claim 1 , further comprising a second transistor connected between the driving transistor and the light-emitting element and operating in a saturation region.
9. The display device of claim 8 , wherein the driving transistor is a p-channel MOS field effect transistor.
10. The display device of claim 9 , wherein the first transistor is an n-channel MOS field effect transistor, and the second transistor is a p-channel MOS field effect transistor.
11. The display device of claim 10 , wherein a control terminal of the first transistor is connected to a first voltage terminal,
a control terminal of the driving transistor is connected to an output terminal of the switching transistor, and
a control terminal of the second transistor is connected to a second voltage terminal.
12. The display device of claim 10 , wherein a control terminal of the first transistor, a control terminal of the driving transistor, and a control terminal of the second transistor are connected to an output terminal of the switching transistor.
13. The display device of claim 12 , wherein a ratio of a channel width to a channel length of the driving transistor is smaller than a ratio of a channel width to a channel length of the second transistor.
14. The display device of claim 8 , wherein the driving transistor is an n-channel MOS field effect transistor.
15. The display device of claim 14 , wherein the first transistor is an n-channel MOS field effect transistor, and the second transistor is a p-channel MOS field effect transistor.
16. The display device of claim 15 , wherein a control terminal of the first transistor is connected to a first voltage terminal,
a control terminal of the driving transistor is connected to an output terminal of the switching transistor, and
a control terminal of the second transistor is connected to a second voltage terminal.
17. The display device of claim 15 , wherein a control terminal of the first transistor, a control terminal of the driving transistor, and a control terminal of the second transistor are connected to an output terminal of the switching transistor.
18. The display device of claim 17 , wherein a ratio of a channel width to a channel length of the driving transistor is smaller than a ratio of a channel width to a channel length of the first transistor.