Display device and driving method of display device

• US 8,743,030 B2
• Filed: 06/11/2010
• Issued: 06/03/2014
• Est. Priority Date: 09/16/2005
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Shishido, Hideaki
• Primary Examiner(s): Eisen, Alexander
• Assistant Examiner(s): MARINELLI, PATRICK
• Application Number:
  US12/813,885
• Publication Number:
  US 20100245219A1
• Time in Patent Office: 1,453 Days
• Field of Search: 345 87-104, 345204-215, 345690-699, 3151691-1694
• US Class Current: 345/80
• CPC Class Codes: G09G 2300/0465 Improved aperture ratio, e.g. by size reduction of the pixel circuit, e.g. for improving the pixel density or the maximum displayable luminance or brightness
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than 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 2310/0251 Precharge or discharge of pixel before applying new pixel 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 2320/0223 Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• 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: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/13 combined with thin-film or thick-film passive components

Abstract

One feature of the present invention includes first to third steps of holding a voltage, corresponding to a difference between a voltage applied to a first power supply line and a threshold voltage of a first transistor, between both electrodes of first and second storage capacitors; holding a voltage, corresponding to a difference between a voltage applied to the first power supply line and a gate-source voltage of the first transistor, which is necessary to supply a light-emitting element with a current equivalent to a video signal current inputted into a signal line, between both the electrodes of the second storage capacitor; and applying a voltage based on the voltage held in the first and second storage capacitors in the first and second steps to a gate electrode of the first transistor; therefore, a current is supplied to the light-emitting element through the first transistor.

Claims

1. A display device comprising:

a pixel portion formed over a face of a substrate, the pixel portion comprising;

a first transistor;

a second transistor;

a third transistor;

a fourth transistor;

a fifth transistor;

a first capacitor;

a second capacitor;

a light-emitting element electrically connected to the fifth transistor, the light-emitting element being configured to emit white light; and

a color filter over the light-emitting element;

a first FPC connected to a first side of the face of the substrate;

a first IC chip over the face of the substrate, the whole of the first IC chip overlapping with the first FPC;

a second FPC connected to a second side of the face of the substrate, the second side being opposite to the first side and the pixel portion being positioned between the first side and the second side; and

a second IC chip over the face of the substrate, the whole of the second IC chip overlapping with the second FPC,

wherein a gate of the first transistor is directly connected to one of a source and a drain of the third transistor,

wherein the gate of the first transistor is directly connected to one of a source and a drain of the fourth transistor,

wherein the gate of the first transistor is directly connected to one of a source and a drain of the second transistor,

wherein the gate of the first transistor is directly connected to a first electrode of the second capacitor,

wherein one of a source and a drain of the first transistor is directly connected to the other one of the source and the drain of the fourth transistor,

wherein the one of the source and the drain of the first transistor is directly connected to one of a source and a drain of the fifth transistor,

wherein the other one of the source and the drain of the second transistor is directly connected to a signal line,

wherein the other one of the source and the drain of the third transistor is directly connected to a first electrode of the first capacitor,

wherein the other one of the source and the drain of the fifth transistor is directly connected to a first electrode of the light-emitting element, and

wherein a second electrode of the first capacitor is electrically connected to a second electrode of the second capacitor.

2. The display device according to claim 1, wherein the first IC chip comprises at least a part of a signal line driver circuit.

3. The display device according to claim 1, wherein the first IC chip comprises at least a part of a scanning line driver circuit.

4. The display device according to claim 1, wherein the first transistor comprises In and Zn.

5. A display device comprising:

a pixel portion formed over a face of a substrate, the pixel portion comprising;

a first transistor;

a second transistor;

a third transistor;

a fourth transistor;

a fifth transistor;

a first capacitor;

a second capacitor;

a light-emitting element electrically connected to the fifth transistor, the light-emitting element being configured to emit white light; and

a color filter over the light-emitting element;

a first FPC connected to a first side of the face of the substrate;

a first IC chip over the face of the substrate, the whole of the first IC chip overlapping with the first FPC;

a second FPC connected to a second side of the face of the substrate, the second side being opposite to the first side and the pixel portion being positioned between the first side and the second side; and

a second IC chip over the face of the substrate, the whole of the second IC chip overlapping with the second FPC;

wherein a gate of the first transistor is directly connected to one of a source and a drain of the second transistor,

wherein the gate of the first transistor is directly connected to one of a source and a drain of the fourth transistor,

wherein the gate of the first transistor is directly connected to a first electrode of the first capacitor,

wherein one of a source and a drain of the first transistor is directly connected to the other one of the source and the drain of the fourth transistor,

wherein the one of the source and the drain of the first transistor is directly connected to one of a source and a drain of the fifth transistor,

wherein the other one of the source and the drain of the second transistor is directly connected to a signal line,

wherein one of a source and a drain of the third transistor is directly connected to a second electrode of the first capacitor,

wherein the one of the source and the drain of the third transistor is directly connected to a first electrode of the second capacitor,

wherein the other one of the source and the drain of the fifth transistor is directly connected to a first electrode of the light-emitting element, and

wherein the other one of the source and the drain of the third transistor is directly connected to a second electrode of the second capacitor.

6. The display device according to claim 5, wherein the first IC chip comprises at least a part of a signal line driver circuit.

7. The display device according to claim 5, wherein the first IC chip comprises at least a part of a scanning line driver circuit.

8. The display device according to claim 5, wherein the first transistor comprises In and Zn.

9. A display device comprising:

a first transistor;

a second transistor;

a third transistor;

a fourth transistor;

a fifth transistor;

a first capacitor;

a second capacitor; and

a light-emitting element,

wherein a gate of the first transistor is directly connected to one of a source and a drain of the third transistor,

wherein the gate of the first transistor is directly connected to one of a source and a drain of the fourth transistor,

wherein the gate of the first transistor is directly connected to one of a source and a drain of the second transistor,

wherein the gate of the first transistor is directly connected to a first electrode of the second capacitor,

wherein one of a source and a drain of the first transistor is directly connected to the other one of the source and the drain of the fourth transistor,

wherein the one of the source and the drain of the first transistor is directly connected to one of a source and a drain of the fifth transistor,

wherein the other one of the source and the drain of the second transistor is directly connected to a signal line,

wherein the other one of the source and the drain of the third transistor is directly connected to a first electrode of the first capacitor,

wherein the other one of the source and the drain of the fifth transistor is directly connected to a first electrode of the light-emitting element, and

wherein a second electrode of the first capacitor is electrically connected to a second electrode of the second capacitor.

10. The display device according to claim 9, wherein the first transistor comprises In and Zn.

11. A display device comprising:

a first transistor;

a second transistor;

a third transistor;

a fourth transistor;

a fifth transistor;

a first capacitor;

a second capacitor; and

a light-emitting element,

wherein a gate of the first transistor is directly connected to one of a source and a drain of the second transistor,

wherein the gate of the first transistor is directly connected to one of a source and a drain of the fourth transistor,

wherein the gate of the first transistor is directly connected to a first electrode of the first capacitor,

wherein one of a source and a drain of the first transistor is directly connected to the other one of the source and the drain of the fourth transistor,

wherein the one of the source and the drain of the first transistor is directly connected to one of a source and a drain of the fifth transistor,

wherein the other one of the source and the drain of the second transistor is directly connected to a signal line,

wherein one of a source and a drain of the third transistor is directly connected to a second electrode of the first capacitor,

wherein the one of the source and the drain of the third transistor is directly connected to a first electrode of the second capacitor,

wherein the other one of the source and the drain of the fifth transistor is directly connected to a first electrode of the light-emitting element, and

wherein the other one of the source and the drain of the third transistor is directly connected to a second electrode of the second capacitor.

12. The display device according to claim 11, wherein the first transistor comprises In and Zn.