Light emitting apparatus including resin banks and electronic device having same

• US 7,242,140 B2
• Filed: 04/23/2003
• Issued: 07/10/2007
• Est. Priority Date: 05/10/2002
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kobayashi, Hidekazu, Miyashita, Satoru
• Primary Examiner(s): Patel; Nimeshkumar D.
• Assistant Examiner(s): HODGES, MATTHEW P
• Application Number:
  US10/420,829
• Publication Number:
  US 20040017335A1
• Time in Patent Office: 1,539 Days
• Field of Search: 313/498, 313/504, 313/506, 313/509, 313/512
• US Class Current: 313/506
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

The invention provides an organic EL apparatus including a substrate, a pair of electrodes formed on the substrate, and a light emitting layer disposed between the electrodes is provided in order to implement a light emitting apparatus and an electronic device which decrease reflections in a display of the organic EL apparatus, and to enhance display quality. The substrate includes a transparent substrate, the pair of the electrodes is an anode disposed on the light emitting layer at the substrate side, and a cathode disposed on the light emitting layer at an opposite side of the substrate. A semi-reflection film is disposed near the anode. The semi-reflection film transmits a part of external light incident on the organic EL apparatus from the substrate, and reflects a part of the light other than the light transmitted.

Claims

1. A light emitting apparatus, comprising:

an organic electroluminescence element including;

a substrate;

a first electrode having a light transmission property;

a second electrode having a light reflection property;

a light emitting layer sandwiched between the first and second electrodes, and the light emitting layer being disposed only inside a boundary defined by overlapping areas of the first and second electrodes;

a semi-reflection film that reflects at least a part of light;

a plurality of pixel apertures on which the light emitting layer is disposed;

spaces between the pixel apertures on which the light emitting layer is not disposed;

resin banks disposed at the spaces;

the first electrode is disposed between the light emitting layer and the semi-reflection film;

a transparent layer and a reflection layer formed on the spaces between the pixels;

a thickness of the transparent layer being set such that a phase of a third reflection light is deviated from a phase of a fourth reflection light at an angle of about 180°

;

the third reflection light being incident on the light emitting apparatus, reflected by the semi-reflection film and exits from the spaces between the pixel; and

the fourth reflection light being transmitted through the semi-reflection film and the transparent layer, and reflected by the reflection layer; and

a thin film transistor, the reflection layer functioning as an electrode of the thin film transistor.

2. The light emitting apparatus as claimed in claim 1, the first and second electrodes being a cathode and an anode, respectively.

3. The light emitting apparatus as claimed in claim 1, the semi-reflection film being disposed on the light emitting layer at the substrate side.

4. The light emitting apparatus as claimed in claim 1,

at least one of the first and second electrodes having a light reflection property;

a thickness of the light emitting layer being set such that first reflection light and second reflection light are interfered and attenuated each other;

the first reflection light being incident on the light emitting apparatus and reflected by the semi-reflection film; and

the second reflection light being reflected by the electrode having the reflection property.

5. The light emitting apparatus as claimed in claim 4, a reflectance of the semi-reflection film being set such that an intensity of the first reflection light is approximately the same as an intensity of the second reflection light.

6. The light emitting apparatus as claimed in claim 1,

at least one of the first and second electrodes having a light reflection property;

a thickness of the light emitting layer being set such that a phase of the first reflection light is deviated from a phase of the second reflection light at an angle of about 180°

;

the first reflection light being incident on the light emitting apparatus and reflected by the semi-reflection film; and

the second reflection light being reflected by the electrode having the light reflection property.

7. The light emitting apparatus as claimed in claim 6, a reflectance of the semi-reflection film being set such that an intensity of the first reflection light is approximately the same as an intensity of the second reflection light.

8. The light emitting apparatus as claimed in claim 1, the semi-reflection film transmitting about 50 percent of the light incident on the semi-reflection film, and reflecting about 50 percent of the light incident thereon.

9. The light emitting apparatus as claimed in claim 1, further including:

a plurality of pixel apertures on which the light emitting layer is disposed, spaces between the pixel apertures on which the light emitting layer is not disposed, a transparent layer and a reflection layer formed on the spaces between the pixels;

a thickness of the transparent layer being set such that a third reflection light and a fourth reflection light are interfered and attenuated each other;

the third reflection light being incident on the spaces between the pixels, reflected by the semi-reflection film and left from the spaces between the pixels; and

the fourth reflection light being transmitted through the semi-reflection film and the transparent layer, and reflected by the reflection layer.

10. The light emitting apparatus as claimed in claim 9, the semi-reflection film being disposed on the spaces between the pixels.

11. The light emitting apparatus as claimed in claim 9, a reflectance of the semi-reflection film being set such that an intensity of the third reflection light is approximately the same as an intensity of the fourth reflection light.

12. The light emitting apparatus as claimed in claim 1, the semi-reflection film being disposed on the spaces between the pixels.

13. The light emitting apparatus as claimed in claim 1, a reflectance of the semi-reflection film being set such that an intensity of the third reflection light is approximately the same as that of the fourth reflection light.

14. The light emitting apparatus as claimed in claim 1, the semi-reflection film being formed near one of the first and second electrodes.

15. The light emitting apparatus as claimed in claim 1, further including a plurality of scanning lines and a plurality of data lines formed in a matrix, a switching device connected to the scanning lines and the data lines, and pixel electrodes connected to the switching device.

16. An electronic device, comprising:

the light emitting apparatus as claimed in claim 1.

17. The light emitting apparatus as claimed in claim 1, including:

a thickness of the resin bank being set such that a phase of a third reflection light is deviated from a phase of a fourth reflection light at an angle of about 180°

;

the third reflection light being incident on the light emitting apparatus, reflected by the semi-reflection film; and

the fourth reflection light being transmitted through the semi-reflection film.