[54] OPTICAL FILM WITH SHARPENED BANDEDGE
[75] Inventors: John A. Wheatley, Ascot, United Kingdom; Michael F. Weber, Shoreview; Andrew J. Ouderkirk,
Woodbury, both of Minn.
[73] Assignee: 3M Innovative Properties Company, St. Paul, Minn.
[ * ] Notice: This patent issued on a continued prosecution application filed under 37 CFR 1.53(d), and is subject to the twenty year patent term provisions of 35 U.S.C. 154(a)(2).
[21] Appl. No.: 09/006,085 [22] Filed: Jan. 13, 1998
[51] Int. CI.7 G02B 5/28; G02B 1/10
[52] U.S. CI 359/589; 359/580; 359/584;
359/590
[58] Field of Search 359/584, 580,
359/586, 588, 589, 590
[56] References Cited
U.S. PATENT DOCUMENTS
Re. 34,605 5/1994 Schrenk et al 359/588
3,124,639 3/1964 Kahn 88/65
3,610,729 10/1971 Rogers 350/157
3,711,176 1/1973 Alfrey, Ir. et al 350/1
3,860,036 1/1975 Newman, Ir. 138/45
4,446,305 5/1984 Rogers et al 528/348
4,520,189 5/1985 Rogers et al 528/331
4,521,588 6/1985 Rogers et al 528/363
4,525,413 6/1985 Rogers et al 428/212
4,720,426 1/1988 Englert et al 428/344
4,747,666 5/1988 Ishida 350/164
4,955,692 9/1990 Merlin et al 359/584
5,103,337 4/1992 Schrenk et al 359/359
5,179,468 1/1993 Gasloli 359/359
5,188,760 2/1993 Hikmet et al 252/299.01
5,211,878 5/1993 Reiffenrath et al 252/299.63
5,235,443 8/1993 Barnik et al 359/37
5,269,995 12/1993 Ramanathan et al 264/171
5,294,657 3/1994 Melendy et al 524/270
5,315,437 5/1994 Alfano et al 359/586
5,316,703 5/1994 Schrenk 264/1.3
5,319,478 6/1994 Fijnfschilling et al 359/53
5,360,659 11/1994 Arends et al 428/216
5,389,324 2/1995 Lewis et al 264/171
5,448,404 9/1995 Schrenk et al 359/584
5,486,935 1/1996 Kalmanash 359/37
5,486,949 1/1996 Schrenk et al 359/498
5,612,820 3/1997 Schrenk et al 359/498
5,629,055 5/1997 Revol et al 428/1
(List continued on next page.)
FOREIGN PATENT DOCUMENTS
WO 93/16878 9/1993 WIPO B32B 27/30
WO 94/10589 5/1994 WIPO G02B 1/10
WO 95/27919 4/1995 WIPO G02B 27/28
WO 95/17303 6/1995 WIPO B32B 7/02
WO 95/17691 6/1995 WIPO G02B 5/30
WO 95/17692 6/1995 WIPO G02B 5/30
WO 95/17699 6/1995 WIPO G02F 1/1335
WO 96/19347 6/1996 WIPO B32B 7/02
WO 97/01440 1/1997 WIPO B32B 27/36
WO 97/01774 1/1997 WIPO G02B 1/10
WO 97/32226 9/1997 WIPO G02B 5/30
OTHER PUBLICATIONS
Schrenk et al., Nanolayer polymeric optical films, Tappi Journal, pp. 169-174, Jun., 1992.
TransmaxTM reflective polarizer product brochure (Jan. 1, 1998).
Primary Examiner—-Thong Nguyen
Assistant Examiner—Jennifer Winstedt
Attorney, Agent, or Firm—Robert J. Pechman
[57] ABSTRACT
The present invention provides reflective films and other optical bodies which exhibit sharp bandedges on one or both sides of the main reflection bands. The optical bodies comprise multilayer stacks Mj and M2, each having first order reflections in a desired part of the spectrum and comprising optical repeating units Rx and R2, respectively. At least one of the optical repeating units Rt and R2 varies monotonically in optical thickness along the thickness of the associated multilayer stack.
36 Claims, 12 Drawing Sheets
