Display device

• US 6,642,665 B2
• Filed: 09/04/2002
• Issued: 11/04/2003
• Est. Priority Date: 01/29/1999
• Status: Expired due to Term

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kimura, Mutsumi
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US10/233,402
• Publication Number:
  US 20020195969A1
• Time in Patent Office: 426 Days
• Field of Search: 315/169.1, 315/169.2, 315/169.3, 345/76, 345/84, 345/90, 345/92, 345/98, 345/211-214
• US Class Current: 315/169.3
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• 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 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3258 with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: H10K 59/121 characterised by the geometry or disposition of pixel elements
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks

Abstract

The invention provides a method and apparatus to obtain accurate gradation by obtaining an accurate ratio of light emitting parts in a display device which implements gradation by forming a plurality of TFTs and a plurality of OELDs in each pixel, directly connecting the TFTs and OELDs, and switching an on and off state of the TFTs, and controlling a light emitting area of the OELDs. A plurality of OELDs have the same shape, and gradation can be implemented by controlling the number of OELDs that emit light. A plurality of OELDs have a round shape. A plurality of OELDs are arranged at the same interval in a vertical and/or horizontal direction. According to this structure, because the light emitting areas of the plurality of OELDs become equal to each other, by controlling the number of OELDs, a ratio of the light emitting areas can be accurately obtained.

Claims

1. A display device, comprising:

a plurality of scanning lines;

a plurality of data lines including a first bit data line and a second bit data line; and

a plurality of pixels, each of the plurality of pixels including;

a plurality of sampling transistors including a first sampling transistor connected to the first bit data line and a second sampling transistor connected to the second bit data line; and

a plurality of light emitting elements including a first group having at least, light emitting element and a second group having a plurality of light emitting elements, the first group being controlled by a data signal supplied through the first bit data line and the first sampling transistor, and the second group being together controlled by a data signal supplied through the second bit data line and the second sampling transistor.

2. The display device according to claim 1,

the plurality of light emitting elements having a same emitting area.

3. The display device according to claim 1,

the plurality of light emitting elements having a same shape.

4. The display device according to claim 1,

each of the plurality of pixels further including a plurality of driving transistors,

the plurality of driving transistors including a first driving transistor and a second driving transistor,

the first driving transistor being connected to the at least one light emitting element included in the first group, and the second driving transistor being connected to the light emitting elements included in the second group.

5. The display device according to claim 1,

gates of the first sampling transistor and the second sampling transistor being connected to one of the plurality of scanning lines.

6. The display device according to claim 4, further comprising a plurality of power supply lines, the plurality of driving transistors being connected to one of the plurality of power supply lines.

7. The display device according to claim 1,

each of the plurality of light emitting elements taking any one of an emissive state and a non-emissive state.

8. The display device according to claim 4,

each of the plurality of driving transistors taking any one of a substantially completely on state and a substantially completely off state.

9. A display device, comprising:

a plurality of scanning lines;

a plurality of data lines including a first bit data line and a second bit data line; and

a plurality of pixels, each of the plurality of pixels including;

a plurality of sampling transistors including a first sampling transistor connected to the first bit data line and a second sampling transistor connected to the second bit data line; and

a plurality of light emitting elements including a first group having one light emitting element and a second group having at least two light emitting elements, the first group being controlled by a data signal supplied through the first bit data line and the first sampling transistor, and the second group being together controlled by a data signal supplied through the second bit data line and the second sampling transistor.

10. The display device according to claim 9,

gates of the first sampling transistor and the second sampling transistor being connected to one of the plurality of scanning lines.

11. The display device according to claim 9,

each of the plurality of pixels further including a plurality of driving transistors,

the plurality of driving transistors including a first driving transistor and a second driving transistor,

the first driving transistor being connected to the one light emitting element included in the first group, and the second driving transistor being connected to the at least two light emitting elements included in the second group.

12. The display device according to claim 11,

each of the plurality of driving transistors taking any one of a substantially completely on state and a substantially completely off state.

13. The display device according to claim 9,

the plurality of light emitting elements having a same emitting area.