Light emitting device, driving method of light emitting device and electronic device

• US 20030062545A1
• Filed: 09/20/2002
• Published: 04/03/2003
• Est. Priority Date: 09/21/2001
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Akiba, Mai, Koyama, Jun, Yamazaki, Shunpei
• Granted Patent: US 6,870,192 B2
• Time in Patent Office: Days
• US Class Current: 257/200
• CPC Class Codes: G09G 2300/04 Structural and physical details of display devices
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2300/0866 by means of changes in the pixel supply voltage
• CPC Class Codes: G09G 2310/0256 with the purpose of reversing the voltage across a light emitting or modulating element within a pixel
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/0291 Details of output amplifiers or buffers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 2330/028 Generation of voltages supplied to electrode drivers in a matrix display other than LCD
• CPC Class Codes: G09G 2330/04 Display protection
• CPC Class Codes: G09G 2330/045 Protection against panel overheating
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/22 : using controlled light sources
• 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 3/3241 : the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror
• CPC Class Codes: G09G 3/325 : the data current flowing through the driving transistor during a setting phase, e.g. by using a switch for connecting the driving transistor to the data driver
• CPC Class Codes: G09G 3/3258 : with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 3/3283 : in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: H01L 27/12 : the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/124 : with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1255 : integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 27/1285 : using control of the annealing or irradiation parameters, e.g. using different scanning direction or intensity for different transistors
• CPC Class Codes: H01L 27/13 : combined with thin-film or thick-film passive components
• CPC Class Codes: H01L 27/15 : including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 29/4908 : for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66757 : Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate
• CPC Class Codes: H01L 33/20 : with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/32 : containing nitrogen
• CPC Class Codes: H10K 2102/103 : comprising indium oxides, e.g. ITO
• CPC Class Codes: H10K 50/846 : comprising getter material or desiccants
• CPC Class Codes: H10K 59/12 : Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/1201 : Manufacture or treatment
• CPC Class Codes: H10K 59/1213 : the pixel elements being TFTs
• CPC Class Codes: H10K 59/1216 : the pixel elements being capacitors
• CPC Class Codes: H10K 59/123 : Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/124 : Insulating layers formed between TFT elements and OLED elements
• CPC Class Codes: H10K 59/131 : Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/1315 : comprising structures specially adapted for lowering the resistance
• CPC Class Codes: H10K 59/874 : including getter material or desiccant
• CPC Class Codes: H10K 85/113 : Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
• CPC Class Codes: H10K 85/114 : Poly-phenylenevinylene; Derivatives thereof
• CPC Class Codes: H10K 85/115 : Polyfluorene; Derivatives thereof
• CPC Class Codes: H10K 85/324 : comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/342 : comprising iridium
• CPC Class Codes: H10K 85/346 : comprising platinum
• CPC Class Codes: H10K 85/631 : Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: H10K 85/6574 : comprising only oxygen in the heteroaromatic polycondensed ring system, e.g. cumarine dyes

Abstract

By controlling the luminance of light emitting element not by means of a voltage to be impressed to the TFT but by means of controlling a current that flows to the TFT in a signal line drive circuit, the current that flows to the light emitting element is held to a desired value without depending on the characteristics of the TFT. Further, a voltage of inverted bias is impressed to the light emitting element every predetermined period. Since a multiplier effect is given by the two configurations described above, it is possible to prevent the luminance from deteriorating due to a deterioration of the organic luminescent layer, and further, it is possible to maintain the current that flows to the light emitting element to a desired value without depending on the characteristics of the TFT.

Claims

1. A light emitting device comprising:

a pixel provided with a light emitting element;

a signal line drive circuit comprising means for generating a current of a magnitude corresponding to a voltage of an input video signal and means for selecting a supply of said generated current or a predetermined voltage to said pixel;

first means provided for said pixel for converting said supplied current to a voltage and further supplying a first current of a magnitude corresponding to said converted voltage to said light emitting element; and

second means provided for said pixel for supplying a second current of a magnitude corresponding to said converted voltage to said light emitting element,

wherein when said predetermined voltage is supplied to said pixel, a voltage of inverted bias is impressed to said light emitting element by said second means.

22. A device according to claim 1 wherein said light emitting device is incorporated into an electronic device.

37. A device according to claim 1 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

2. A light emitting device comprising:

a pixel comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a light emitting element, a power supply line, a signal line and a power supply that controls a voltage between said power supply line and the counter electrode of said light emitting element; and

a signal line drive circuit comprising first means for generating a current of a magnitude corresponding to a voltage of an input video signal and second means for selecting a supply of said generated current or a predetermined voltage to said signal line,

wherein the gate of said third transistor and the gate of said fourth transistor are connected to each other,

wherein one of a first terminal and a second terminal of said third transistor is connected to said signal line ,and another one thereof is connected to a second terminal of said first transistor,

wherein one of a first terminal and a second terminal of said fourth transistor is connected to the second terminal of said first transistor ,and another one thereof is connected to the gate of said first transistor;

wherein the first terminal of said first transistor is connected to said power supply line and the second terminal thereof is connected to a first terminal of said second transistor,

wherein the second terminal of said second transistor is connected to a pixel electrode included in said light emitting element,

wherein said predetermined voltage is of a magnitude that turns ON said first transistor,

wherein when said second transistor is turned ON by said predetermined voltage, a voltage of inverted bias is impressed to said light emitting element by said power supply.

4. A device according to claim 2, wherein said third transistor and said fourth transistor have the same polarity.

23. A device according to claim 2 wherein said light emitting device is incorporated into an electronic device.

38. A device according to claim 2 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

3. A light emitting device comprising:

a pixel comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a light emitting element, a power supply line, a signal line and a power supply that controls a voltage between said power supply line and the counter electrode of said light emitting element; and

a signal line drive circuit comprising first means for generating a current of a magnitude corresponding to a voltage of an input video signal and second means for selecting a supply of said generated current or a predetermined voltage to said signal line,

wherein the gates of said third and fourth transistors are connected to each other,

wherein one of a first terminal and a second terminal of said third transistor is connected to said signal line ,and another one thereof is connected to the gate of said first transistor,

wherein one of a first terminal and a second terminal of said fourth transistor is connected to said signal line ,and another one thereof is connected to a second terminal of said first transistor,

wherein a first terminal of said first transistor is connected to said power supply line,

wherein a first terminal and a second terminal of said second transistor are connected respectively to the second terminal of said first transistor and a pixel electrode included in said light emitting element,

wherein said predetermined voltage is of a magnitude that turns ON said first transistor, and

wherein when said second transistor is turned ON by said predetermined voltage, a voltage of inverted bias is impressed to said light emitting element by said power supply.

5. A device according to claim 3, wherein said third transistor and said fourth transistor have the same polarity.

24. A device according to claim 3 wherein said light emitting device is incorporated into an electronic device.

39. A device according to claim 3 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

6. A light emitting device comprising:

a pixel comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a light emitting element, a power supply line, a signal line and a power supply that controls a voltage between said power supply line and a counter electrode of said light emitting element; and

a signal line drive circuit comprising first means for generating a current of a magnitude corresponding to a voltage of an input video signal and second means for selecting a supply of said generated current or a predetermined voltage to said signal line,

wherein one of a first terminal and a second terminal of said fourth transistor is connected to said signal line, and another one thereof is connected to a second terminal of said first transistor,

wherein one of a first terminal and a second terminal of said fifth transistor is connected to said signal line, and another one thereof is connected to the gate of said third transistor,

wherein both of first terminals of said first transistor and said second transistor are connected to said power supply line,

wherein the gate of said first transistor is connected to the gate and a second terminal of said second transistor,

wherein a first terminal of said third transistor is connected to the second terminal of said second transistor, and said second terminal is connected to a pixel electrode included in said light emitting element,

wherein said predetermined voltage is of a magnitude that turns ON said second transistor, and

wherein when said second transistor is turned ON by said predetermined voltage, a voltage of inverted bias is impressed to said light emitting element by said power supply.

14. A device according to claim 6, wherein said first transistor and said second transistor have a same polarity.

25. A device according to claim 6 wherein said light emitting device is incorporated into an electronic device.

40. A device according to claim 6 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

7. A light emitting device comprising:

a pixel comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a light emitting element, a power supply line, a signal line and a power supply that controls a voltage between said power supply line and a counter electrode of said light emitting element; and

a signal line drive circuit comprising first means for generating a current of a magnitude corresponding to a voltage of an input video signal and second means for selecting a supply of said generated current or a predetermined voltage to said signal line,

wherein both of first terminals of said first transistor and said second transistor are connected to said power supply line,

wherein the gates of said first transistor and said second transistor are connected to each other,

wherein one of a first terminal and a second terminal of said third transistor is connected to said signal line, and another one thereof is connected to a second terminal of said first transistor,

wherein one of a first terminal and a second terminal of said fourth transistor is connected to a second terminal of said first transistor or said signal line, and another one thereof is connected to the gates of said first and said second transistors,

wherein one of a first terminal and a second terminal of said fifth transistor is connected to the second terminal of said first transistor, and another one thereof is connected to a second terminal of said second transistor,

wherein the second terminal of said second transistor is connected to a pixel electrode of said light emitting element,

wherein said predetermined voltage is of a magnitude that turns ON said second transistor, and

wherein when said second transistor is turned ON by said predetermined voltage, a voltage of inverted bias is impressed to said light emitting element by said power supply.

15. A device according to claim 7, wherein said first transistor and said second transistor have a same polarity.

26. A device according to claim 7 wherein said light emitting device is incorporated into an electronic device.

41. A device according to claim 7 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

8. A light emitting device comprising:

a pixel comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a light emitting element, a power supply line, a signal line and a power supply that controls a voltage between said power supply line and a counter electrode of said light emitting element; and

a signal line drive circuit comprising first means for generating a current of a magnitude corresponding to a voltage of an input video signal and second means for selecting a supply of said generated current or a predetermined voltage to said signal line,

wherein the gates of said first transistor and said second transistor are connected to each other,

wherein one of a first terminal and a second terminal of said third transistor is connected to said signal line, and another one thereof is connected to first terminals of said first and said second transistors,

wherein one of a first terminal and a second terminal of said fourth transistor is connected to the gates of said first and said second transistors, and another one thereof is connected to said power supply line,

wherein one of a first terminal and a second terminal of said sixth transistor is connected to said power supply line, and another one thereof is connected to a second terminal of said second transistor,

wherein one of a first terminal and a second terminal of said fifth transistor is connected to first terminals of said first and said second transistors, and another one thereof is connected to a pixel electrode of said light emitting element,

wherein said predetermined voltage is of a magnitude that turns ON said second transistor, and

wherein when said second transistor is turned ON by said predetermined voltage, a voltage of inverted bias is impressed to said light emitting element by said power supply.

16. A device according to claim 8, wherein said first transistor and said second transistor have a same polarity.

27. A device according to claim 8 wherein said light emitting device is incorporated into an electronic device.

42. A device according to claim 8 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

9. A light emitting device comprising:

a pixel comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a light emitting element, a power supply line, a signal line and a power supply that controls a voltage between said power supply line and a counter electrode of said light emitting element; and

a signal line drive circuit comprising first means for generating a current of a magnitude corresponding to a voltage of an input video signal and second means for selecting a supply of said generated current or a predetermined voltage to said signal line,

wherein the gates of said first transistor and said second transistor are connected to each other,

wherein both of the second terminals of said first transistor and said second transistor are connected to said power supply line,

wherein one of a first terminal and a second terminal of said third transistor is connected to said signal line, and another one thereof is connected to first terminals of said first and said second transistors,

wherein one of a first terminal and a second terminal of said fourth transistor is connected to the gates of said first and said second transistors, and another one thereof is connected to said power supply line,

wherein one of a first terminal and a second terminal of said sixth transistor is connected to the first terminal of said second transistor, and another one thereof is connected to a first terminal of said first transistor,

wherein one of a first terminal and a second terminal of said fifth transistor is connected to a first terminal of said first transistor, and another one thereof is connected to a pixel electrode of said light emitting element,

wherein said predetermined voltage is of a magnitude that turns ON said second transistor, and

wherein when said second transistor is turned ON by said predetermined voltage, a voltage of inverted bias is impressed to said light emitting element by said power supply.

17. A device according to claim 9, wherein said first transistor and said second transistor have a same polarity.

28. A device according to claim 9 wherein said light emitting device is incorporated into an electronic device.

43. A device according to claim 9 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

10. A light emitting device comprising:

a pixel comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a light emitting element, a power supply line, a signal line and a power supply that controls a voltage between said power supply line and a counter electrode of said light emitting element; and

a signal line drive circuit comprising first means for generating a current of a magnitude corresponding to a voltage of an input video signal and second means for selecting a supply of said generated current or a predetermined voltage to said signal line,

wherein both of first terminals of said first transistor and said second transistor are connected to said power supply line,

wherein the gates of said first transistor and said second transistor are connected to each other,

wherein one of a first terminal and a second terminal of said third transistor is connected to said signal line, and another one thereof is connected to a second terminal of said first transistor,

wherein one of a first terminal and a second terminal of said fourth transistor is connected to a second terminal of said first transistor or said signal line, and another one thereof is connected to the gates of said first and said second transistors,

wherein one of a first terminal and a second terminal of said fifth transistor is connected to a second terminal of said sixth transistor, and another one thereof is connected to a second terminal of said second transistor,

wherein the gate of said sixth transistor is connected to the gates of said first and said second transistors,

wherein a first terminal of said sixth transistor is connected to the second terminal of said first transistor,

wherein the second terminal of said second transistor is connected to a pixel electrode of said light emitting element,

wherein said predetermined voltage is of a magnitude that turns ON said second transistor, and

wherein when said second transistor is turned ON by said predetermined voltage, a voltage of inverted bias is impressed to said light emitting element by said power supply.

18. A device according to claim 10, wherein said first transistor and said second transistor have a same polarity.

29. A device according to claim 10 wherein said light emitting device is incorporated into an electronic device.

44. A device according to claim 10 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

11. A light emitting device comprising:

a pixel comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a light emitting element, a power supply line, a signal line and a power supply that controls a voltage between said power supply line and a counter electrode of said light emitting element; and

a signal line drive circuit comprising first means for generating a current of a magnitude corresponding to a voltage of an input video signal and second means for selecting a supply of said generated current or a predetermined voltage to said signal line,

wherein the gates of said first transistor and said second transistor are connected to each other,

wherein one of a first terminal and a second terminal of said third transistor is connected to said signal line, and another one thereof is connected to a second terminal of said first transistor,

wherein one of a first terminal and a second terminal of said fourth transistor is connected to a second terminal of said first transistor or said signal line, and another one thereof is connected to the gates of said first and said second transistors

wherein one of a first terminal and a second terminal of said fifth transistor is connected to a second terminal of said second transistor and said power supply line, and another one thereof is connected to the second terminal of said first transistor,

wherein first terminals of said first and said second transistors are connected to a pixel electrode of said light emitting element,

wherein said predetermined voltage is of a magnitude that turns ON said second transistor, and

wherein when said second transistor is turned ON by said predetermined voltage, a voltage of inverted bias is impressed to said light emitting element by said power supply.

19. A device according to claim 11, wherein said first transistor and said second transistor have a same polarity.

45. A device according to claim 11 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

12. A light emitting device comprising:

a pixel comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a light emitting element, a power supply line, a signal line and a power supply that controls a voltage between said power supply line and a counter electrode of said light emitting element; and

a signal line drive circuit comprising first means for generating a current of a magnitude corresponding to a voltage of an input video signal and second means for selecting a supply of said generated current or a predetermined voltage to said signal line,

wherein the gates of said first transistor and said second transistor are connected to each other,

wherein one of a first terminal and a second terminal of said third transistor is connected to said signal line, and another one thereof is connected to a second terminal of said first transistor,

wherein one of a first terminal and a second terminal of said fourth transistor is connected to a second terminal of said first transistor or said signal line, and another one thereof is connected to the gates of said first and said second transistors,

wherein one of a first terminal and a second terminal of said fifth transistor is connected to a second terminal of said second transistor and said power supply line, and another one thereof is connected to a second terminal of said sixth transistor,

wherein a first terminal of said sixth transistor is connected to the second terminal of said first transistor,

wherein first terminals of said first and said second transistors are connected to a pixel electrode of said light emitting element,

wherein said predetermined voltage is of a magnitude that turns ON said second transistor,

wherein when said second transistor is turned ON by said predetermined voltage, a voltage of inverted bias is impressed to said light emitting element by said power supply.

20. A device according to claim 12, wherein said first transistor and said second transistor have a same polarity.

46. A device according to claim 12 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

13. A light emitting device comprising:

a pixel comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a light emitting element, a power supply line, a signal line and a power supply that controls a voltage between said power supply line and a counter electrode of said light emitting element; and

a signal line drive circuit comprising first means for generating a current of a magnitude corresponding to a voltage of an input video signal and second means for selecting a supply of said generated current or a predetermined voltage to said signal line,

wherein the gates of said first transistor and said second transistor are connected to each other,

wherein one of a first terminal and a second terminal of said third transistor is connected to said signal line, and another one thereof is connected to a first terminal of said first transistor,

wherein one of a first terminal and a second terminal of said fourth transistor is connected to a second terminal of said first transistor, and another one thereof is connected to the gates of said first and said second transistors,

wherein one of a first terminal and a second terminal of said fifth transistor is connected to a first terminal of said first transistor, and another thereof is connected to a first terminal of said second transistor,

wherein second terminals of said first and said second transistors are connected to said power supply line,

wherein a first terminal of said second transistor is connected to a pixel electrode of said light emitting element,

wherein said predetermined voltage is of a magnitude that turns ON said second transistor, and

wherein when said second transistor is turned ON by said predetermined voltage, a voltage of inverted bias is impressed to said light emitting element by said power supply.

21. A device according to claim 13, wherein said first transistor and said second transistor have a same polarity.

30. A method of driving a light emitting device in which a first period, a second period and a third period appear in one frame period, comprising:

in said first, said second and said third periods, gates of a first transistor and a second transistor included in said light emitting device being connected to each other, the gate and a second terminal of said second transistor being connected to each other, the second terminal of said second transistor being connected to a first terminal of a third transistor included in said light emitting device, a second terminal of said third transistor being connected to a pixel electrode of a light emitting element included in said light emitting device;

in said first period, connecting a second terminal of said first transistor to the gate of said third transistor to allow a current determined by a voltage of a video signal to flow between a first terminal and the second terminal of said first transistor, and further, impressing a first voltage to the first terminals of said first and said second transistors;

in said second period, electrically separating the second terminal of said first transistor from the gate of said third transistor, and further, impressing said first voltage to the first terminals of said first and said second transistors;

in said third period, connecting the second terminal of said first transistor to the gate of said third transistor to impress a second voltage to the gates of said first and second transistors to turn ON said second transistor, and further, impressing a third voltage to the first terminals of said first and second transistors;

the polarity of said first voltage and said third voltage being inverted with respect to a voltage of an counter electrode of said light emitting element; and

the voltage impressed to said light emitting element in said third period having an inverted bias.

47. A method according to claim 30 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

31. A method of driving a light emitting device in which a first period, a second period and a third period appear in one frame period, comprising:

in said first, said second and said third period, a gate of first transistor and a second terminal included in said light emitting device being connected to each other, the second terminal of said first transistor being connected to a first terminal of a second transistor included in said light emitting device, a second terminal of said second transistor being connected to a pixel electrode of a light emitting element included in said light emitting device;

in said first period, allowing a current determined by a voltage of a video signal to flow between a first terminal of said first transistor and the second terminal thereof, and further, impressing a first voltage to the first terminal of said first transistor to turn OFF said second transistor;

in said second period, impressing said first voltage to the first terminal of said first transistor to turn OFF said second transistor;

in said third period, impressing a second voltage to the gate of said first transistor to turn ON said first transistor, and further, impressing a third voltage to the first terminal of said first transistor to turn ON said second transistor;

the polarity of said first voltage and said third voltage being inverted with respect to a voltage of an counter electrode of said light emitting element; and

the voltage impressed to said light emitting element in said third period having an inverted bias.

48. A method according to claim 31 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

32. A method of driving a light emitting device in which a first period, a second period and a third period appear in one frame period, comprising:

in said first, said second and said third period, a second terminal of a first transistor included in said light emitting device being connected to a first terminal of a second transistor included in said light emitting device, a second terminal of said second transistor being connected to a pixel electrode of a light emitting element included in said light emitting device;

in said first period, connecting a gate of said first transistor and the second terminal thereof to each other to allow a current determined by a voltage of a video signal to flow between a first terminal and the second terminal of said first transistor, and further, impressing a first voltage to the first terminal of said first transistor, and turning OFF said second transistor;

in said second period, impressing said first voltage to the first terminal of said first transistor to turn ON said second transistor, electrically separating the gate of said first transistor and the second terminal thereof;

in said third period, connecting the gate of said first transistor and the second terminal thereof, impressing a second voltage to the gate of said first transistor to turn ON said first transistor, and further, impressing a third voltage to the first terminal of said first transistor to turn ON said second transistor;

the polarity of said first voltage and said third voltage being inverted with respect to a voltage of an counter electrode of said light emitting element; and

the voltage impressed to said light emitting element in said third period having an inverted bias.

49. A method according to claim 32 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

33. A method of driving a light emitting device in which a first period, a second period and a third period appear in one frame period, comprising:

in said first, said second and said third period, gates of a first transistor and a second transistor included in said light emitting device being connected to each other, a second terminal of said second transistor being connected to a pixel electrode of a light emitting element included in said light emitting device;

in said first period, allowing a current determined by a voltage of a video signal to flow between a first terminal of said first transistor and a second terminal thereof to impress a first voltage to the first terminals of said first and said second transistors, and further, connecting the gate and the second terminal of said first transistor to each other;

in said second period, electrically separating the second terminal of said first transistor and the gate thereof from each other, and further, impressing said first voltage to the first terminals of said first and said second transistors;

in said third period, connecting the gate of said first transistor and the second terminal thereof to each other and impressing a second voltage to the gates of said first and second transistors to turn ON said second transistor, and further, impressing a third voltage to the first terminals of said first and second transistors;

the polarity of said first voltage and said third voltage being inverted with respect to a voltage of an counter electrode of said light emitting element; and

the voltage impressed to said light emitting element in said third period having an inverted bias.

50. A method according to claim 33 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

34. A method of driving a light emitting device in which a first period, a second period and a third period appear in one frame period, comprising:

in said first, said second and said third period, gates of a first transistor and a second transistor included in said light emitting device being connected to each other, first terminals of said first transistor and said second transistor being connected to a second terminal of a third transistor included in said light emitting device, a first terminal of said third transistor being connected to a pixel electrode of a light emitting element included in said light emitting device;

in said first period, allowing a current determined by a voltage of a video signal to flow between a first terminal of said first transistor and a second terminal thereof, impressing a first voltage to a second terminal of said first transistor, connecting the gate of said first transistor and the second terminal thereof to each other, and further, turning OFF said third transistor,

in said second period, electrically separating the second terminal of said first transistor and the gate thereof from each other, impressing said first voltage to the second terminals of said first and said second transistors, and further, turning ON said third transistor;

in said third period, connecting the gate of the said first transistor and the second terminal thereof to each other to impress a second voltage to the gates of said first and second transistors, thereby turning ON said second transistor, and further, impressing a third voltage to the second terminal of said first transistor, and furthermore, turning ON said third transistor;

the polarity of said first voltage and said third voltage being inverted with respect to a voltage of an counter electrode of said light emitting element; and

the voltage impressed to said light emitting element in said third period having an inverted bias.

51. A method according to claim 34 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

35. A method of driving a light emitting device in which a first period, a second period and a third period appear in one frame period, comprising:

in said first, said second and said third period, gates of a first transistor and a second transistor included in said light emitting device being connected to each other, a first terminal of said second transistor being connected to a second terminal of a third transistor included in said light emitting device, a first terminal of said third transistor being connected to a pixel electrode of a light emitting element included in said light emitting device;

in said first period, allowing a current determined by a voltage of a video signal to flow between a first terminal of said first transistor and a second terminal thereof, impressing a first voltage to a second terminals of said first transistor and second transistors, connecting the gate of said first transistor and the second terminal thereof to each other, and further, turning OFF said third transistor;

in said second period, electrically separating the second terminal of said first transistor and the gate thereof from each other, impressing said first voltage to the second terminals of said first and said second transistors, and further, turning ON said third transistor;

in said third period, connecting the gate of said first transistor to the second terminal thereof to impress a second voltage to the gates of said first and second transistors, thereby, turning ON said second transistor, and further, impressing a third voltage to the second terminals of said first transistor and said second transistor, and furthermore, turning ON said third transistor;

the polarity of said first voltage and said third voltage being inverted with respect to a voltage of an counter electrode of said light emitting element; and

the voltage impressed to said light emitting element in said third period having an inverted bias.

52. A method according to claim 35 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.

36. A method of driving a light emitting device in which a first period, a second period and a third period appear in one frame period, comprising:

in said first, said second and said third period, gates of a first transistor and a second transistor included in said light emitting device being connected to each other, a second terminal of said second transistor being connected to a pixel electrode of a light emitting element included in said light emitting device;

in said first period, connecting a second terminal of said first transistor and a gate thereof to each other, allowing a current determined by a voltage of a video signal to flow between a first terminal of said first transistor and a second terminal thereof, and further, impressing a first voltage to the first terminals of said first and said second transistors;

in said second period, electrically separating the second terminal of said first transistor and the gate thereof from each other, connecting the gates of said first transistor and said second transistor to a gate of a third transistor included in said light emitting device, connecting the second terminal of said first transistor and a first terminal of said third transistor, connecting a second terminal of said third transistor to a pixel electrode of said light emitting element, and further, impressing said first voltage to the first terminals of said first and said second transistors;

in said third period, connecting the second terminal of said first transistor and the gate thereof, impressing a second voltage to the gates of said first and second transistors, thereby turning ON said second transistor, and further, impressing a third voltage to the first terminals of said first and second transistors, electrically separating the second terminal of said first transistor and the pixel electrode of said light emitting element from each other;

the polarity of said first voltage and said third voltage being inverted with respect to a voltage of an counter electrode of said light emitting element; and

the voltage impressed to said light emitting element in said third period having an inverted bias.

53. A method according to claim 36 wherein said light emitting device is incorporated into one selected from the group consisting of a digital still camera, a lap-top computer, a mobile computer, a portable image reproduction apparatus, a head mounted display, a video camera, and a mobile phone.