Display unit, array display and display panel utilizing the same and control method thereof

• US 7,619,594 B2
• Filed: 10/11/2005
• Issued: 11/17/2009
• Est. Priority Date: 05/23/2005
• Status: Active Grant

• Current Assignee: Optronic Sciences LLC (Lumina Innovations LLC)
• Original Assignee: AU Optronics Corporation
• Inventors: Hu, Shuo-Hsiu
• Primary Examiner(s): Awad; Amr
• Assistant Examiner(s): MATTHEWS, ANDRE L
• Application Number:
  US11/247,414
• Publication Number:
  US 20060262047A1
• Time in Patent Office: 1,498 Days
• Field of Search: 345/76
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/3225 using an active matrix

Abstract

A display unit is provided. The display unit includes a light-emitting diode, a driving transistor, and a power supply system. The light-emitting diode comprises a cathode and an anode. The driving transistor comprises a source, a drain, and a gate, wherein the gate receives a first voltage, the drain is coupled to a second voltage via the light-emitting diode and the gate receives a third voltage. The power supply system is coupled to the drain of the driving transistor, providing the second voltage in response to the voltage of the drain of the driving transistor.

Claims

1. A display unit, comprising:

a light-emitting diode comprising a cathode and an anode;

a driving transistor comprising a source, a drain and a gate, wherein the source is adapted to receive a first voltage, the drain is coupled to a second voltage via the light-emitting diode, and the gate is adapted to receive a third voltage;

a power supply system having a first terminal and a second terminal;

a first resistor coupled between the drain of the driving transistor and the first terminal; and

a second resistor coupled between the first terminal and a ground;

wherein the power supply system provides the second voltage according to the voltage of the drain of the driving transistor, the resistance value of the first resistor, and the resistance value of the second resistor.

2. The display unit of claim 1, further comprising:

a reference voltage source;

a switch transistor comprising a gate, a first electrode and a second electrode, wherein the gate is adapted to receive a scan signal, the first electrode is adapted to receive a data signal, and the second electrode is coupled to the gate of the driving transistor; and

a storage capacitor coupled between the second electrode of the switch transistor and the reference voltage source.

3. The display unit of claim 1, wherein the driving transistor is a PMOS transistor.

4. The display unit of claim 3, wherein the second voltage is less than the first voltage, the anode of the light-emitting diode is coupled to the drain of the driving transistor, and the cathode of the light-emitting diode is adapted to receive the second voltage.

5. The display unit of claim 1, wherein the driving transistor is an NMOS transistor.

6. The display unit of claim 5, wherein the second voltage is greater than the first voltage, the cathode of the light-emitting diode is coupled to the drain of the driving transistor, and the anode of the light-emitting diode is adapted to receive the second voltage.

7. The display unit of claim 1, wherein the power supply system comprises a DC-DC converter.

8. The display unit of claim 1, wherein the power supply system provides the second voltage according to an equation Vss=Vd(R1/R2+1), Vss represent a value of the second voltage, Vd represents a value of the voltage of the drain of the driving transistor, R1 represents the resistance value of the first resistor, and R2 represents the resistance value of the second resistor.

9. The display unit of claim 1, wherein the power supply system provides the second voltage according to the voltage of the drain of the driving transistor, the resistance value of the first resistor, and the resistance value of the second resistor for maintaining the driving transistor in a saturation region.

10. An array display, comprising:

a plurality of data lines;

a plurality of scan lines crossing the data lines;

a plurality of display units, each corresponding to one set of data and scan lines and comprising;

a light-emitting diode comprising a cathode and an anode; and

a driving transistor comprising a source, a drain and a gate, wherein the source is adapted to receive a first voltage, the drain is coupled to a second voltage via the light-emitting diode, and the gate is adapted to receive a third voltage;

a power supply system having a first terminal and a second terminal;

a first resistor coupled between the drain of at least one driving transistor and the first terminal; and

a second resistor coupled between the first terminal and a ground;

wherein the power supply system provides the second voltage according to the voltage of the drain of the driving transistor, the resistance value of the first resistor, and the resistance value of the second resistor.

11. The array display of claim 10, wherein each display unit comprises:

a reference voltage source;

a switch transistor comprising;

a gate coupled to a corresponding scan line and adapted to receive a scan signal;

a first electrode coupled to a corresponding data line and adapted to receive a data signal; and

a second electrode coupled to the gate of the driving transistor; and

a storage capacitor coupled between the second electrode of the switch transistor and the reference voltage source.

12. The array display of claim 10, wherein the driving transistor is a PMOS transistor.

13. The array display of claim 12, wherein the second voltage is less than the first voltage, the anode of the light-emitting diode is coupled to the drain of the driving transistor, and the cathode of the light-emitting diode is adapted to receive the second voltage.

14. The array display of claim 10, wherein the driving transistor is an NMOS transistor.

15. The array display of claim 14, wherein the second voltage is greater than the first voltage, the cathode of the light-emitting diode is coupled to the drain of the driving transistor, and the anode of the light-emitting diode is adapted to receive the second voltage.

16. The array display of claim 10, wherein the power supply system comprises a DC-DC converter.

17. The array display of claim 10, wherein the power supply system provides the second voltage according to an equation Vss=Vd(R1/R2+1), Vss represent a value of the second voltage, Vd represents a value of the voltage of the drain of the driving transistor, R1 represents the resistance value of the first resistor, and R2 represents the resistance value of the second resistor.

18. The array display of claim 10, wherein the power supply system provides the second voltage according to the voltage of the drain of the driving transistor, the resistance value of the first resistor, and the resistance value of the second resistor for maintaining the driving transistor in a saturation region.

19. A display panel, comprising:

a plurality of data lines;

a plurality of scan lines crossing the data lines;

a data driver, coupled to the data lines, for applying a plurality of data signals to the data lines;

a scan driver, coupled to the scan lines, for applying a plurality of data signals to the scan lines;

a plurality of display units, each corresponding to one set of the data and scan lines and comprising;

a light-emitting diode comprising a cathode and an anode; and

a driving transistor comprising a source, a drain and a gate, wherein the source is adapted to receive a first voltage, the drain is coupled to a second voltage via the light-emitting diode, and the gate is adapted to receive a third voltage;

a power supply system having a first terminal and a second terminal;

a first resistor coupled between the drain of at least one driving transistor and the first terminal; and

a second resistor coupled between the first terminal and a ground;

wherein the power supply system provides the second voltage according to the voltage of the drain of the driving transistor, the resistance value of the first resistor, and the resistance value of the second resistor.

20. The display panel of claim 19, wherein each display unit further comprises:

a reference voltage source;

a switch transistor comprising;

a gate coupled to a corresponding scan line and adapted to receive one scan signal;

a first electrode coupled to a corresponding data line and adapted to receive one data signal; and

a second electrode coupled to the gate of the driving transistor; and

a storage capacitor coupled between the second electrode of the switch transistor and the reference voltage source.

21. The display panel of claim 19, wherein the driving transistor is a PMOS transistor.

22. The display panel of claim 21, wherein the second voltage is less than the first voltage, the anode of the light-emitting diode is coupled to the drain of the driving transistor, and the cathode of the light-emitting diode is adapted to receive the second voltage.

23. The display panel of claim 19, wherein the driving transistor is an NMOS transistor.

24. The display panel of claim 23, wherein the second voltage is greater than the first voltage, the cathode of the light-emitting diode is coupled to the drain of the driving transistor, and the anode of the light-emitting diode is adapted to receive the second voltage.

25. The display panel of claim 19, wherein the power supply system comprises a DC-DC converter.

26. The display panel of claim 19, wherein the power supply system provides the second voltage according to an equation Vss=Vd(R1/R2+1), Vss represent a value of the second voltage, Vd represents a value of the voltage of the drain of the driving transistor, R1 represents the resistance value of the first resistor, and R2 represents the resistance value of the second resistor.

27. The display panel of claim 19, wherein the power supply system provides the second voltage according to the voltage of the drain of the driving transistor, the resistance value of the first resistor, and the resistance value of the second resistor for maintaining the driving transistor in a saturation region.