Display device and electronic apparatus

• US 20040256620A1
• Filed: 06/09/2004
• Published: 12/23/2004
• Est. Priority Date: 06/17/2003
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koyama, Jun, Yamazaki, Shunpei
• Granted Patent: US 7,224,118 B2
• Time in Patent Office: Days
• US Class Current: 257/66
• CPC Class Codes: G09G 2300/0417 Special arrangements specific to the use of low carrier mobility technology
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• 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 2300/0842 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 2310/0251 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 2310/0286 Details of a shift registers arranged for use in a driving circuit
• 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 3/2022 using sub-frames
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 29/78669 with inverted-type structure, e.g. with bottom gate
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/486 the channel region comprising two or more active layers, e.g. forming pn heterojunctions
• CPC Class Codes: H10K 19/10 comprising field-effect transistors
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 59/131 : Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/805 : Electrodes

Abstract

A display device in which variations in luminance due to variations in characteristics of transistors are reduced, and image quality degradation due to variations in resistance values is prevented. The invention comprises a transistor whose channel portion is formed of an amorphous semiconductor or an organic semiconductor, a connecting wiring connected to a source electrode or a drain electrode of the transistor, a light emitting element having a laminated structure which includes a pixel electrode, an electro luminescent layer, and a counter electrode, an insulating layer surrounding an end portion of the pixel electrode, and an auxiliary wiring formed in the same layer as a gate electrode of the transistor, a connecting wiring, or the pixel electrode. Further, the connecting wiring is connected to the pixel electrode, and the auxiliary wiring is connected to the counter electrode via an opening portion provided in the insulating layer.

Claims

1. A display device comprising:

a transistor whose channel portion is formed of an amorphous semiconductor or an organic semiconductor;

a connecting wiring connected to a source electrode or a drain electrode of the transistor;

a light emitting element having a laminated structure which includes a pixel electrode, an electro luminescent layer, and a counter electrode;

an insulating layer surrounding an end portion of the pixel electrode; and

an auxiliary wiring formed in the same layer as either a gate electrode of the transistor, the connecting wiring, or the pixel electrode,

wherein the connecting wiring is connected to the pixel electrode; and

the auxiliary wiring is connected to the counter electrode via an opening portion provided in the insulating layer.

2. A device according to claim 1, further comprising a driver IC for controlling the transistor and the light emitting element,

wherein the driver IC is attached over a substrate including the transistor and the light emitting element.

3. A device according to claim 1, further comprising a driver IC for controlling the transistor and the light emitting element,

wherein the driver IC is connected to a connecting film which is attached over a substrate including the transistor and the light emitting element.

4. A device according to claim 1, wherein the transistor is a channel etched type transistor.

5. A device according to claim 1, wherein the transistor is a channel protected type transistor.

6. A device according to claim 1, wherein the transistor is a dual gate type transistor.

7. A device according to claim 1, wherein the light emitting element and the transistor are formed over a flexible substrate.

8. A device according to claim 1, further comprising a reverse bias voltage applying circuit for applying a reverse bias voltage to the light emitting element.

9. An electronic apparatus using the display device according to claim 1.

10. A display device comprising:

a transistor whose channel portion is formed of an amorphous semiconductor or an organic semiconductor;

a connecting wiring connected to a source electrode or a drain electrode of the transistor;

a light emitting element having a laminated structure which includes a pixel electrode, an electro luminescent layer, and a counter electrode;

an insulating layer surrounding an end portion of the pixel electrode;

an auxiliary wiring formed in the same layer as either a gate electrode of the transistor, the connecting wiring, or the pixel electrode; and

a driver circuit controlling the transistor and the light emitting element,

wherein the connecting wiring is connected to the pixel electrode;

the auxiliary wiring is connected to the counter electrode via an opening portion provided in the insulating layer; and

the driver circuit comprises at least one of an N-type transistor whose channel portion is formed of an amorphous semiconductor and a P-type transistor whose channel portion is formed of an organic semiconductor.

11. A device according to claim 10, further comprising a driver IC for controlling the transistor and the light emitting element,

wherein the driver IC is attached over a substrate including the transistor and the light emitting element.

12. A device according to claim 10, further comprising a driver IC for controlling the transistor and the light emitting element,

wherein the driver IC is connected to a connecting film which is attached over a substrate including the transistor and the light emitting element.

13. A device according to claim 10, wherein the transistor is a channel etched type transistor.

14. A device according to claim 10, wherein the transistor is a channel protected type transistor.

15. A device according to claim 10, wherein the transistor is a dual gate type transistor.

16. A device according to claim 10, wherein the light emitting element and the transistor are formed over a flexible substrate.

17. A device according to claim 10, further comprising a reverse bias voltage applying circuit for applying a reverse bias voltage to the light emitting element.

18. An electronic apparatus using the display device according to claim 10.