Optical unit and organic light emitting diode display having the same

• US 20120098422A1
• Filed: 09/22/2011
• Published: 04/26/2012
• Est. Priority Date: 10/25/2010
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Jung, Woo-Suk, Park, Soon-Ryong
• Granted Patent: US 8,810,114 B2
• Time in Patent Office: Days
• US Class Current: 313/512
• CPC Class Codes: G02F 1/133502 Antiglare, refractive index matching layers
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G02F 2201/16 series; tandem
• CPC Class Codes: H10K 2102/3023 Direction of light emission
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 50/868 Arrangements for polarized light emission H10K50/86 takes precedence
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

An optical unit on a light emitting unit includes a first polarizing plate on the light emitting unit, a second polarizing plate on the first polarizing plate, the second polarizing plate having a higher polarization degree than the first polarizing plate, and a plurality of phase shift plates between the first polarizing plate and the second polarizing plate.

Claims

1. An optical unit on a light emitting unit, comprising:

a first polarizing plate on the light emitting unit;

a second polarizing plate on the first polarizing plate, the second polarizing plate having a higher polarization degree than the first polarizing plate; and

a plurality of phase shift plates between the first polarizing plate and the second polarizing plate.

2. The optical unit as claimed in claim 1, wherein:

the first polarizing plate has a higher transmittance than the second polarizing plate.

3. The optical unit as claimed in claim 2, the first polarizing plate comprising:

a matrix;

an iodine; and

a dye.

4. The optical unit as claimed in claim 3, wherein:

a weight ratio of the iodine and the dye is in a range of about 1;

1 to about 1;

2.

5. The optical unit as claimed in claim 1, wherein:

an intersection angle between a polarization axis of the first polarizing plate and a polarization axis of the second polarizing plate is about 45 degrees.

6. The optical unit as claimed in claim 5, the plurality of phase shift plates comprising:

a first phase shift plate between the first polarizing plate and the second polarizing plate, wherein the first phase shift plate is a ½

wavelength plate;

a second phase shift plate between the first polarizing plate and the first phase shift plate, wherein the second phase shift plate is a ¼

wavelength plate; and

a third phase shift plate between the first polarizing plate and the second phase shift plate, wherein the third phase shift plate is a ¼

wavelength plate.

7. The optical unit as claimed in claim 6, wherein:

an intersection angle between a polarization axis of the second polarizing plate and an optical axis of the first phase shift plate is in a range of about 17.5 degrees to about 27.5 degrees, and

an intersection angle between a polarization axis of the first polarizing plate and an optical axis of the first phase shift plate is in a range of about 17.5 degrees and to about 27.5 degrees.

8. The optical unit as claimed in claim 7, wherein:

an intersection angle between a polarization axis of the second polarizing plate and an optical axis of the second phase shift plate is in a range of about 40 degrees to about 50 degrees, and

an intersection angle between a polarization axis of the first polarizing plate and an optical axis of the second phase shift plate is in a range of about 0 degrees to about 5 degrees.

9. The optical unit as claimed in claim 8, wherein:

an intersection angle between a polarization axis of the second polarizing plate and an optical axis of the third phase shift plate is in a range of about 85 degrees to about 90 degrees, and

an intersection angle between a polarization axis of the first polarizing plate and an optical axis of the third phase shift plate is in a range of about 40 degrees to about 50 degrees.

10. The optical unit as claimed in claim 9, wherein:

an intersection angle between an optical axis of the second phase shift plate and an optical axis of the third phase shift plate is about 45 degrees.

11. The optical unit as claimed in claim 5, the plurality of phase shift plates comprising:

a fourth phase shift plate between the first polarizing plate and the second polarizing plate, wherein the fourth phase shift plate is a ½

wavelength plate; and

a fifth phase shift plate between the first polarizing plate and the fourth phase shift plate, wherein the fifth phase shift plate is a ¼

wavelength plate.

12. The optical unit as claimed in claim 11, wherein:

an intersection angle between a polarization axis of the second polarizing plate and an optical axis of the fourth phase shift plate is in a range of about 10 degrees to about 20 degrees, and

an intersection angle between a polarization axis of the first polarizing plate and an optical axis of the fourth phase shift plate is in a range of about 25 degrees to about 35 degrees.

13. The optical unit as claimed in claim 12, wherein:

an intersection angle between a polarization axis of the second polarizing plate and an optical axis of the fifth phase shift plate is in a range of about 70 degrees to about 80 degrees, and

an intersection angle between a polarization axis of the first polarizing plate and an optical axis of the fifth phase shift plate is in a range of about 25 degrees to about 35 degrees.

14. The optical unit as claimed in claim 1, further comprising:

a sixth phase shift plate between the light emitting unit and the first polarizing plate.

15. The optical unit as claimed in claim 14, wherein:

an intersection angle between an optical axis of the sixth phase shift plate and a polarization axis of the first polarizing plate is in a range of about 40 degrees to about 50 degrees.

16. An organic light emitting diode (OLED) display, comprising:

an organic light emitting element for emitting light,

wherein the organic light emitting element includes a first electrode, a second electrode on the first electrode, and an organic emission layer between the first electrode and the second electrode; and

the optical unit of claim 1 on the organic light emitting element.