Current-driven light-emitting display apparatus and method of producing the same

• US 6,462,722 B1
• Filed: 10/02/1998
• Issued: 10/08/2002
• Est. Priority Date: 02/17/1997
• Status: Expired due to Term

• Current Assignee: Intellectual Keystone Technology LLC
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kimura, Mutsumi, Itoh, Tomoyuki
• Primary Examiner(s): Mengistu, Amare
• Application Number:
  US09/155,644
• Time in Patent Office: 1,467 Days
• Field of Search: 345/76, 345/77, 345/52, 345/34, 345/42, 349/42, 315/169.3
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0417 Special arrangements specific to the use of low carrier mobility technology
• CPC Class Codes: G09G 2300/0439 Pixel structures
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0866 by means of changes in the pixel supply voltage
• CPC Class Codes: G09G 2300/0876 Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: G09G 3/3291 in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H05B 44/00 Circuit arrangements for operating electroluminescent light sources for operating light emitting diodes H05B45/00
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

An organic EL display device driven by thin-film transistors is disclosed, wherein for suppressing the deterioration with time of thin-film transistors, at least one of the thin-film transistors, or a second thin-film transistor is formed of a p-channel type thin-film transistor. The p-channel type thin-film transistor has been formed in the same step of process as the thin-film transistors in built-in drive circuits.

Claims

1. A display apparatus, comprising:

a plurality of scanning lines;

a plurality of data lines;

a plurality of pixels corresponding to intersections of the plurality of scanning lines and the plurality of data lines, one of the plurality of pixels comprising;

a luminescent element;

a first transistor of which gate and source or drain are connected to one of the plurality of scanning lines and one of the plurality of data lines, respectively;

a holding capacitor; and

a second transistor of which a gate is connected to the holding capacitor, the second transistor being a p-channel type transistor and the second transistor being disposed in series with the current luminescent element.

2. The display apparatus according to claim 1,

the second transistor controlling current that flows through the luminescent element.

3. The display apparatus according to claim 1,

the first transistor and the second transistor being thin-film transistors.

4. The display apparatus according to claim 3,

further comprising a first driving circuit connected to the plurality of scanning lines and a second driving circuit connected to a plurality of data lines, each of the first driving circuit and the second driving circuit comprising a thin-film transistor.

5. The display apparatus according to claim 4,

the thin-film transistor of at least one of the first and the second driving circuits being formed in a same step of process as at least one of the first transistor and the second transistor.

6. The display apparatus according to claim 3,

further comprising a first driving circuit connected to the plurality of scanning lines and a second driving circuit connected to the plurality of data lines, at least one of the first driving circuit and the second driving circuit comprising an n-channel type thin-film transistor and a p-channel type thin-film transistor.

7. A method for manufacturing the display apparatus according to claim 6, comprising:

forming the first transistor in a same step of process as the n-channel type thin-film transistor, and

forming the second transistor in a same step process as the p-channel type thin-film transistor.

8. The display apparatus according to claim 3,

the first transistor and the second transistor being polysilicon thin-film transistors.

9. The display apparatus according to claim 1,

further comprising a first driving circuit connected to the plurality of scanning lines and a second driving circuit connected to the plurality of data lines.

10. The display apparatus according to claim 9,

each of the first driving circuit and the second driving circuit comprising a transistor.

11. The display apparatus according to claim 10,

at least one of the first driving circuit and the second driving circuit comprising at least one of a shift register circuit, a level shifter circuit, and an analog switch.

12. The display apparatus according to claim 1, the first transistor being an n-channel type transistor.

13. The display apparatus according to claim 1, the luminescent element being an organic EL element.

14. The display apparatus according to claim 1, a source or drain of the first transistor begin connected to the holding capacitor through a potential holding electrode.

15. The display apparatus according to claim 1, the first transistor being connected to the holding capacitor through a potential holding electrode.

16. A display apparatus, comprising:

a plurality of scanning lines;

a plurality of data lines;

an opposite electrode; and

a plurality of pixels corresponding to intersections of the plurality of scanning lines and the plurality of data lines, one of the plurality of pixels comprising;

a luminescent element;

a first transistor of which a gate and a source or drain are connected to one of the plurality of scanning lines and one of the plurality of data lines, respectively;

a holding capacitor;

a second transistor of which a gate. is connected to the holding capacitor, the second transistor begin a p-channel type; and

the luminescent element being disposed between the opposite electrode and the second transistor.

17. The display apparatus according to claim 16,

the second transistor controlling current that flows through the luminescent element.

18. The display apparatus according to claim 16,

the first transistor and the second transistor being thin-film transistors.

19. The display apparatus according to claim 18,

further comprising a first driving circuit connected to the plurality of scanning lines and a second driving circuit connected to the plurality of data lines, each of the first driving circuit and the second driving circuit comprising a thin-film transistor.

20. The display apparatus according to claim 19, the thin-film transistor of at least one of the first and the second driving circuits being formed in a same step of process as at least one of the first transistor and the second transistor.

21. The display apparatus according to claim 18, further comprising a first driving circuit connected to the plurality of scanning lines and a second driving circuit connected to the plurality of data lines, at least one of the first driving circuit and the second driving circuit comprising an n-channel type thin-film transistor and a p-channel type thin film transistor.

22. The display apparatus according to claim 16,

further comprising a first driving circuit connected to the plurality of scanning lines and a second driving circuit connected to the plurality of data lines.

23. The display apparatus according to claim 22,

each of the first driving circuit and the second driving circuit comprising a transistor.

24. The display apparatus according to claim 22,

at least one of the first driving circuit and the second driving circuit comprising at least one of a shift register circuit, a level shifter circuit, and an analog switch.

25. The display apparatus according to claim 16, the first transistor being an n-channel type transistor.

26. The display apparatus according to claim 16, the luminescent element begin an organic EL element.

27. The display apparatus according to claim 16, the first transistor being connected to the holding capacitor through a potential holding electrode.

28. A display apparatus, comprising:

a plurality of scanning lines;

a plurality of data lines;

a plurality of pixels corresponding to intersections of the plurality of scanning lines and the plurality of data lines, one of the plurality of pixels comprising;

a luminescent element;

a first transistor of which a gate and a source or drain are connected to one of the plurality of scanning lines and one of the plurality of data lines, respectively

a holding capacitor;

a second transistor of which a gate is connected to the holding capacitor, the second transistor begin a p-channel type transistor;

a current that flows through the second transistor flowing through the luminescent element.

29. The current-driven light-emitting display apparatus of claim 28, the p-channel type thin-film transistor being formed of polysilicon.

30. The display apparatus according to claim 28, the first transistor begin an n-channel type transistor.

31. The display apparatus according to claim 28, the luminescent element begin an organic EL element.