Granted Patent B2

US 12,474,515 · App. 17/780,581 · Granted Nov 18, 2025

Inventors: Takashi Fujita (Kanagawa, JP); Hideaki Shirotori (Kanagawa, JP); Chikara Abe (Yamagata, JP); Matthew B. Johnson (Woodbury, MN); Brianna N. Wheeler (Bloomington, MN); Adam D. Haag (Woodbury, MN)

Assignee: 3M INNOVATIVE PROPERTIES COMPANY

G02B5/305

Abstract

Claims (24)

1 . An optical stack comprising:

a reflective polarizer comprising a plurality of interference layers; and

an absorbing polarizer disposed on and substantially co-extensive with the reflective polarizer, such that for a substantially normally incident light and for at least a first wavelength between about 450 nm and about 670 nm:

each interference layer reflects or transmits light primarily by optical interference;

the plurality of interference layers transmits at least about 85% of the incident light having a first polarization state, reflects at least about 80% of the incident light having an orthogonal second polarization state, and transmits less than about 0.1% of the incident light having the second polarization state;

the absorbing polarizer has a first optical transmittance for the first polarization state, an optical absorption greater than about 50% for the second polarization state, and a second optical transmittance for the second polarization state, an average of the first and second optical transmittances greater than about 0.46, the second optical transmittance having a first standard deviation across at least 80% of the absorbing polarizer, the first standard deviation greater than about 0.004; and

the optical stack has an optical transmittance for the second polarization state having a second standard deviation across at least 80% of the optical stack, the second standard deviation less than about 0.001.

2 . The optical stack of claim 1 , wherein the first wavelength is about 550 nm.

3 . The optical stack of claim 1 , wherein each interference layer has an average thickness less than about 500 nm.

4 . The optical stack of claim 1 , wherein the absorbing polarizer is bonded to the reflective polarizer.

5 . The optical stack of claim 1 , wherein the absorbing polarizer is coated on the reflective polarizer.

6 . The optical stack of claim 1 , wherein the first standard deviation is greater than about 0.005.

7 . The optical stack of claim 1 , wherein the second standard deviation is less than about 0.0001.

8 . The optical stack of claim 1 , wherein for a substantially normally incident unpolarized light and for a first wavelength range of about 450 nm to about 650 nm:

the absorbing polarizer has an optical transmittance averaged over the first wavelength range having a third standard deviation across at least 80% of the absorbing polarizer; and

the optical stack has an optical transmittance averaged over the first wavelength range having a fourth standard deviation across at least 80% of the optical stack, the fourth standard deviation less than the third standard deviation by at least about 10%.

9 . The optical stack of claim 8 , wherein the third standard deviation is greater than about 0.005.

10 . A display comprising:

a display panel;

an extended light source configured to provide illumination to the display panel; and

the optical stack of claim 1 disposed between the display panel and the extended light source, the absorbing polarizer facing the display panel, the reflective polarizer facing the extended light source.

11 . The optical stack of claim 1 , wherein the first standard deviation divided by the second standard deviation is at least about 10.

12 . The optical stack of claim 1 , wherein the first standard deviation divided by the second standard deviation is at least about 100.

13 . The optical stack of claim 1 , wherein the first standard deviation divided by the second standard deviation is at least about 400.

Assignments (1)

Continuity (2)

References Cited (22)