Display device, method for driving display device, and electronic apparatus

• US 9,064,450 B2
• Filed: 03/05/2008
• Issued: 06/23/2015
• Est. Priority Date: 03/14/2007
• Status: Active Grant

• Current Assignee: JDI Design and Development GK
• Original Assignee: JOLED Inc.
• Inventors: Kashiwabara, Mitsuhiro
• Primary Examiner(s): Karimi, Pegeman
• Application Number:
  US12/042,842
• Publication Number:
  US 20080224968A1
• Time in Patent Office: 2,666 Days
• Field of Search: 345/83, 345/76, 345/204, 345/690
• US Class Current: 1/1
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: H10K 59/351 comprising more than three subpixels, e.g. red-green-blue-white [RGBW]
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]

Abstract

Disclosed herein is a display device including: a red pixel configured to be provided with a red light-emitting element that generates red light; a green pixel configured to be provided with a green light-emitting element that generates green light; and two blue pixels configured to be provided with blue light-emitting elements that generate blue light and have the same structure, wherein a color filter is provided on a light-extraction side of at least one of the two blue pixels so that blue light beams having different y-values in an xy chromaticity coordinate system are extracted from the two blue pixels.

Claims

1. A display device comprising:

a red pixel provided with a red light-emitting element that generates red light;

a green pixel provided with a green light-emitting element that generates green light;

a first blue pixel emitting blue light having a first y-value in an xy chromaticity coordinate system, wherein the first blue pixel is provided with a first blue light emitting element that generates blue light;

a second blue pixel emitting blue light having a second y-value in the xy chromaticity coordinate system different from the first y-value, wherein the second blue pixel is provided with a second blue light emitting element that generates blue light, and wherein the first blue light emitting element and the second blue light emitting element are made of a same material having a same lifetime characteristic and that generates a same blue light; and

a blue color filter provided on a light-extraction side of the first blue pixel that extracts blue light beams from the blue light generated by the first blue light emitting element.

2. The display device according to claim 1, wherein

a chromaticity coordinate of blue light extracted from one of the first and second blue pixels is located in a direction toward a center among a chromaticity coordinate of red light extracted from the red pixel, a chromaticity coordinate of green light extracted from the green pixel, and a chromaticity coordinate of blue light extracted from the other of the first and second blue pixels.

3. The display device according to claim 1, wherein

each of the light-emitting elements is an organic electroluminescence element.

4. The display device according to claim 1, wherein

each of the light-emitting elements has a resonator structure that allows resonance of light of a respective one of colors.

5. The display device according to claim 4, wherein

the resonator structure comprises a separate light-emission functional layer for each of said red pixel, said green pixel, said first blue pixel, and said second blue pixel.

6. The display device according to claim 5, wherein

the light-emission functional layer comprises a light-emitting layer and at least one of a hole injection layer, a hole transport layer, an electron transport layer, or an electron injection layer.

7. The display device according to claim 1, wherein the same material is ADN (9,10-di(2-naphthyl)anthracene) and perylene.

8. The display device according to claim 1, wherein each of the first and the second blue light emitting elements include a light emission functional layer having a first end and a second end, and

an optical distance L between the first end and the second end satisfies:

L=(m−

Φ

/2π

)λ

/2

wherein m is an order, Φ

is a sum of a phase shift of reflected light arising at the first end and a phase shift of reflected light arising at the second end, and λ

is a peak wavelength of a spectrum of light desired to be extracted through the second end.

9. The display device according to claim 1, wherein the blue color filter absorbs external light reflected by the first blue light-emitting element.

10. The display device according to claim 1, further comprising:

a dark blue color filter provided on a light-extraction side of the second blue pixel that extracts blue light having a y-value in the xy chromaticity coordinate system lower than blue light obtained through the blue color filter.

11. The display device according to claim 10, wherein each of the first blue pixel provided with the blue color filter and the second blue pixel provided with the dark blue color filer emit light from respective light emitting elements.

12. A method for driving a display device including a red pixel provided with a red light-emitting element that generates red light, a green pixel provided with a green light-emitting element that generates green light, a first blue pixel emitting blue light having a first y-value in an xy chromaticity coordinate system, wherein the first blue pixel is provided with a first blue light emitting element that generates blue light, a second blue pixel emitting blue light having a second y-value in the xy chromaticity coordinate system different from the first y-value, wherein the second blue pixel is provided with a second blue light emitting element that generates blue light, and wherein the first blue light emitting element and the second blue light emitting element are made of a same material having a same lifetime characteristic and that generates a same blue light, a blue color filter provided on a light-extraction side of the first blue pixel that extracts blue light beams from the blue light generated by the first blue light emitting element, the method comprising:

driving only the red pixel, the green pixel, and one of the first and second blue pixels for displaying in which colors can be represented by these three pixels; and

driving the red pixel, the green pixel, and both of the first and second blue pixels only for displaying in which color representation is impossible unless these four pixels are used.

13. Electronic apparatus including a display panel, the display panel comprising:

a red pixel provided with a red light-emitting element that generates red light;

a green pixel provided with a green light-emitting element that generates green light;

a first blue pixel emitting blue light having a first y-value in an xy chromaticity coordinate system, wherein the first blue pixel is provided with a first blue light emitting element that generates blue light;

a second blue pixel emitting blue light having a second y-value in the xy chromaticity coordinate system different from the first y-value, wherein the second blue pixel is provided with a second blue light emitting element that generates blue light, and wherein the first blue light emitting element and the second blue light emitting element are made of a same material having a same lifetime characteristic and that generates a same blue light; and

a blue color filter provided on a light-extraction side of the first blue pixel that extracts blue light beams from the blue light generated by the first blue light emitting element.