US 12,092,838 B2
Polarization beam splitter and hot mirror for heads up display
Craig R. Schardt, Woodbury, MN (US); Adam D. Haag, Woodbury, MN (US); and Stephen J. Willet, St. Paul, MN (US)
Assigned to 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
Filed on Jul. 12, 2023, as Appl. No. 18/220,934.
Application 18/220,934 is a division of application No. 17/795,065, granted, now 11,740,480, previously published as PCT/IB2021/050641, filed on Jan. 27, 2021.
Claims priority of provisional application 62/968,240, filed on Jan. 31, 2020.
Prior Publication US 2023/0350217 A1, Nov. 2, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 27/10 (2006.01); G02B 5/28 (2006.01); G02B 27/01 (2006.01)
CPC G02B 27/1013 (2013.01) [G02B 5/282 (2013.01); G02B 27/0101 (2013.01); G02B 2027/0145 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An optical system comprising:
an optical stack comprising an absorbing polarizer stacked on a first reflective polarizer; and
a display and a mirror disposed on a same side of, and generally facing, the optical stack, the first reflective polarizer disposed between the absorbing polarizer and the display and the mirror, the optical system configured to display a virtual image of an image emitted by the display to a viewer after the emitted image is at least once reflected by the optical stack, such that for a substantially normally incident light, a visible wavelength range extending from about 420 nm to about 680 nm, and an infrared wavelength range extending from about 900 nm to about 1150 nm:
for at least one infrared wavelength in the infrared wavelength range, the first reflective polarizer reflects at least 60% of the incident light having a first polarization state and transmits at least 60% of the incident light having an orthogonal second polarization state; and
for at least one visible wavelength in the visible wavelength range, the absorbing polarizer absorbs at least 60% of the incident light having the first polarization state and transmits at least 60% of the incident light having the second polarization state.