Display driving device and display device including the same
Provided are a display driving device capable of accurately detecting characteristics of pixels of a display panel regardless of an offset of an amplifier, and a display device including the same. The display device includes a display panel including pixels and a display driving device including a sense circuit configured to detect pixel signals from the pixels. The sense circuit includes sense amplifiers configured to provide the first reference voltage to the pixels so that the pixels are programmed using a first reference voltage in a programming mode.
1. A display device comprising:
a display panel comprising pixels; and
a display driving device comprising a sense circuit configured to detect pixel signals from the pixels,
wherein the sense circuit comprises sense amplifiers configured to provide a first reference voltage to the pixels so that the pixels are programmed using the first reference voltage in a programming mode,
wherein each of the pixels comprises:
an organic light emitting diode (OLED); and
a driving transistor configured to supply a current to the OLED,
wherein the pixels are programmed using a sum of the first reference voltage and a threshold voltage of the driving transistor in the programming mode subsequent to an initialization mode.
2. The display device of claim 1 , wherein the sense amplifier operates as a unit gain amplifier in the programming mode.
3. The display device of claim 2 , wherein in the programming mode, the sense amplifier has a negative input stage and an output stage coupled, and provides a data line of the pixel with the first reference voltage applied to a positive input stage of the sense amplifier.
4. The display device of claim 1 , wherein the sense amplifier operates as an integrator in a sensing mode subsequent to the programming mode.
5. The display device of claim 4 , wherein the sense amplifier operates as the integrator after providing a data line of the pixel with a second reference voltage applied to a positive input stage of the sense amplifier in the sensing mode.
6. The display device of claim 5 , wherein the second reference voltage is set as a lower level than the first reference voltage.
7. The display device of claim 1 , wherein each of the pixels and the sense amplifier are coupled through a data line.
8. The display device of claim 1 , wherein each of the pixels comprises:
a first transistor configured to couple a source terminal of the driving transistor and a data line;
a second transistor configured to couple a drain terminal of the driving transistor and a first power supply voltage terminal;
a third transistor configured to couple the source terminal of the driving transistor and the OLED;
a fourth transistor configured to couple the drain terminal of the driving transistor and a gate terminal of the driving transistor;
a capacitor configured to have one end coupled to the fourth transistor and the gate terminal and the other end coupled to a fifth transistor and to store charges; and
the fifth transistor configured to couple the other end of the capacitor and an initial voltage terminal,
wherein the OLED has one end coupled to the third transistor and the other end coupled to a second power supply voltage terminal, and
the other end of the capacitor and the one end of the OLED are coupled.
9. The display device of claim 8 , wherein an initial voltage of the initial voltage terminal is set as a level equal to or lower than a level of a second power supply voltage of the second power supply voltage terminal.
10. The display device of claim 8 , wherein in the initialization mode, a first node of the gate terminal is initialized as a first power supply voltage by turning off the first and third transistors and turning on the second, fourth and fifth transistors.
11. The display device of claim 10 , wherein in the programming mode subsequent to the initialization mode, the first node of the gate terminal is programmed using a sum of the first reference voltage and a threshold voltage of the driving transistor by turning off the second and third transistors and turning on the first, fourth and fifth transistors.
12. The display device of claim 11 , wherein in the sensing mode subsequent to the programming mode, the pixel signal is detected by turning off the third, fourth and fifth transistors and turning on the first and second transistors.
13. A display driving device comprising:
a sense circuit configured to detect pixel signals from pixels of a display panel,
wherein the sense circuit comprises a sense amplifiers configured to provide a first reference voltage to the pixels so that the pixels are programmed using the first reference voltage in a programming mode,
wherein each of the pixels comprises:
an organic light emitting diode (OLED); and
a driving transistor configured to supply a current to the OLED,
wherein the pixels are programmed using a sum of the first reference voltage and a threshold voltage of the driving transistor in the programming mode subsequent to an initialization mode.
14. The display driving device of claim 13 , wherein the sense amplifier transmits the first reference voltage to a data line of the pixel in the programming mode.
15. The display driving device of claim 14 , wherein the sense amplifier detects the pixel signal through the data line in a sensing mode subsequent to the programming mode.
16. The display driving device of claim 13 , wherein in the programming mode, the sense amplifier operates as a unit gain amplifier and provides a data line of the pixel with the first reference voltage applied to an input stage of the sense amplifier.
17. The display driving device of claim 13 , wherein in a sensing mode subsequent to the programming mode, the sense amplifier provides a second reference voltage to a data line of the pixel and operates as an integrator.
18. The display driving device of claim 17 , wherein the second reference voltage is set as a lower level than the first reference voltage.
19. A display device comprising:
a display panel comprising pixels;
a display driving device comprising a sense circuit configured to detect pixel signals from the pixels, wherein the sense circuit comprises a sense amplifiers configured to provide a first reference voltage to the pixels so that the pixels are programmed using the first reference voltage in a programming mode; and
a controller configured to control the pixels and the sense circuit in an initialization mode in which the pixels are initialized, the programming mode in which the pixels are programmed, and a sensing mode in which the pixel signals are detected;
wherein each of the pixels comprises:
an organic light emitting diode (OLED); and
a driving transistor configured to supply a current to the OLED,
wherein the pixels are programmed using a sum of the first reference voltage and a threshold voltage of the driving transistor in the programming mode subsequent to an initialization mode.
20. The display device of claim 19 , wherein the controller controls the pixels so that the pixels are initialized using a first power supply voltage in the initialization mode, controls the pixels and the sense amplifier so that the pixels are programmed using the first reference voltage of the sense amplifier in the programming mode, and controls the pixels and the sense amplifier so that the pixel signals are detected by the sense amplifier in the sensing mode.