(12) United States Patent
Fukuoka et al.
(io) Patent No.: US 6,469,438 B2 (45) Date of Patent: Oct. 22,2002
(54) ORGANIC ELECTROLUMINESCENCE DEVICE WITH PRESCRIBED OPTICAL PATH LENGTH
(75) Inventors: Kenichi Fukuoka; Mitsuru Eida, both of Sodegaura (JP)
(73) Assignee: Idemitsu Kosan Co., Ltd. (JP)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 09/727,454
(22) Filed: Dec. 4, 2000
(65) Prior Publication Data
US 2001/0000943 Al May 10, 2001
Related U.S. Application Data
(63) Continuation of application No. PCT/1P00/02182, filed on Apr. 4, 2000.
(30) Foreign Application Priority Data
Apr. 5, 1999 (IP) 11-097727
(51) Int. CI.7 H05B 33/14; H05B 33/22
(52) U.S. CI 313/504; 313/506
(58) Field of Search 313/504, 503,
313/501, 506; 257/89
6,091,195 A * 7/2000 Forrest et al 313/504
FOREIGN PATENT DOCUMENTS
EP 0 653 902 Al 5/1995 H05B/33/12
IP 5-3081 1/1993 H05B/33/22
IP 7-78689 3/1995 H05B/33/26
IP 7-240277 9/1995 H05B/33/12
* cited by examiner
Primary Examiner—Michael H. Day
(74) Attorney, Agent, or Firm—Parkhurst & Wendel, L.L.P
An organic ELECTROLUMINESCENCE device exhibiting a minimal change in the color purity (CIE chromaticity coordinates) even if there is some fluctuation in the optical path length, and a method of manufacturing such an organic EL device are provided.
The organic EL device contains an organic layer formed between electrodes at least one of which is a transparent electrode, wherein the total optical path length (t) of the transparent electrode and the organic layer satisfies the following inequality (a) or inequality (b) or both:
Min-20 nm<r<Min+20 nm (a)
Max-20 nm<r<Max+20 nm (b)
wherein t is the total optical path length (nm), Min is the optical path length (nm) at which the CIEx chromaticity coordinates or CIEy chromaticity coordinates measured according to JIS Z 8701 exhibits a minimum value, and Max is the optical path length (nm) at which the CIEx chromaticity coordinates or CIEy chromaticity coordinates measured according to JIS Z 8701 exhibit a maximum value.
7 Claims, 35 Drawing Sheets