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US 2026/0140295 A1Published application
Multilayer Reflective Polarizer with Crystalline Low Index Layers
Assignee3M Innovative Properties Company
InventorsAdam D. Haag, Matthew B. Johnson, Carl A. Stover, Timothy J. Nevitt, William F. Edmonds, Stephen A. Johnson
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Abstract
Multilayer reflective polarizers are described. In particular, multilayer reflective polarizers that include both crystalline high index layers and low index layers are disclosed. These reflective polarizers may be particularly suitable for combiner applications, including automotive heads up display applications with demanding ambient environments.
Claims6
An optical laminate, comprising:
- a multilayer reflective polarizer comprising a plurality of alternating first polymer layers and second polymer layers;
- and
- a mirror film laminated to the multilayer reflective polarizer:
- wherein the mirror film reflects less than 20% of visible light, and at least 80% of light from 900-1200 nm,
- wherein the first polymer layers include polyethylene terephthalate:
- wherein the second polymer layers include a glycol-modified co (polyethylene terephthalate);
- and
- wherein an f-ratio of the multilayer reflective polarizer, defined as a ratio of an average optical thickness of the first polymer layers to the total optical thickness of both the first polymer layers and the second polymer layers, is at least 0.55.
5 more elements
A laminate, comprising:
- a multilayer reflective polarizer comprising a plurality of alternating first polymer layers and second polymer layers;
- and
- a glass layer:
- wherein the multilayer reflective polarizer is laminated to the glass:
- wherein each of the first polymer layers and the second polymer layers has an in-plane birefringence of at least 0.04:
- wherein for at least one in-plane direction, the difference in refractive index between each of the first polymer layers and the second polymer layers is at least 0.04;
- wherein for a second in-plane direction orthogonal to the at least one in-plane direction, the difference in refractive index between each of the first polymer layers and the second polymer layers is less than 0.04;
- and
- wherein the multilayer reflective polarizer has at least four edges.
6 more elements
A multilayer reflective polarizer, comprising:
- a plurality of alternating first polymer layers and second polymer layers:
- wherein each of the first polymer layers and the second polymer layers has an in-plane birefringence of at least 0.04;
- wherein for at least one in-plane direction, the difference in refractive index between each of the first polymer layers and the second polymer layers is at least 0.04;
- wherein for a second in-plane direction orthogonal to the at least one in-plane direction, the difference in refractive index between each of the first polymer layers and the second polymer layers is less than 0.04;
- wherein the multilayer reflective polarizer has at least four edges;
- and
- wherein after a 232° C. (450° F.) annealing for 30 seconds, a transmission spectrum of the reflective polarizer from 400 nm to 800 nm drops by no more than 10%.
4 more elements
Dependencies are inferred from the claim text.