Granted Patent B2

US 12,276,821 · App. 18/638,160 · Granted Apr 15, 2025

Inventors: Robert M. Jennings (Shoreview, MN); Jo A. Etter (Stillwater, MN); Susan L. Kent (Shorewood, MN); Erin A. McDowell (Afton, MN); Timothy L. Wong (West St. Paul, MN); Zhisheng Yun (Sammamish, WA)

Assignee: 3M INNOVATIVE PROPERTIES COMPANY

G02B5/3033G02B5/10G02B5/3041G02B5/3066G02B27/0172G02B2003/0093G02B2027/013

Abstract

Claims (12)

1. A device, comprising:

at least one optical film and having an active area that is curved along a first direction and along an orthogonal second direction, wherein:

a portion of the active area has a sag to diameter ratio, S/D, greater than 0.025;

there is at least one point, p 0 , on the surface of the active area such that a surface normal direction at p 0 is parallel to a normal vector of a reference plane of the active area;

each point, p, on the surface of the active area has a linear polarization block axis orientation angle between a measured block axis tangent direction at p and a local reference tangent direction at p, the local reference tangent direction being coplanar with the normal vector of the reference plane and the measured block axis tangent direction at p 0 ; and

a maximum variation of linear polarization block axis angles for all points of the portion of the active area, β max −β min , is less than 22(S/D) degrees.

2. A device, comprising:

at least one optical film and having an active area that is curved along a first direction and along an orthogonal second direction, wherein:

a portion of the active area has a sag to diameter ratio, S/D, greater than 0.025;

there is at least one point, p 0 , on the surface of the active area such that a surface normal direction at p 0 is parallel to a normal vector of a reference plane of the active area;

each point, p, on the surface of the active area has a linear polarization pass axis orientation angle between a measured pass axis tangent direction at p and a local reference tangent direction at p, the local reference tangent direction being coplanar with the normal vector of the reference plane and the measured pass axis tangent direction at p 0 ; and

a maximum variation of linear polarization pass axis angles for all points of the portion of the active area, α max −α min , is less than 550(S/D) 2 +3.5(S/D) degrees.

Continuity (4)

References Cited (37)