Rearview assembly incorporating high-transmittance NIR film
A rearview assembly includes an electrochromic element. The electrochromic element includes a first substrate including a first surface and a second surface. The electrochromic element further includes a second substrate comprising a third surface and a fourth surface. The first substrate and the second substrate form a cavity. The electrochromic element includes an electrochromic medium contained in the cavity. The rearview assembly includes an image sensor directed toward the fourth surface and configured to capture near-infrared light reflected from an object and projected through the electrochromic element. The rearview assembly includes a transflective film disposed adjacent to the fourth surface having a near-infrared light transmission level and a visible light reflectance level.
1. A rearview assembly comprising:
an electrochromic element comprising:
a first substrate comprising a first surface and a second surface;
a second substrate comprising a third surface and a fourth surface, wherein the first substrate and the second substrate form a cavity; and
an electrochromic medium contained in the cavity;
an image sensor directed toward the fourth surface and configured to capture near-infrared light reflected off of an object and transmitted through the electrochromic element; and
a transflective film disposed adjacent to the fourth surface having a near-infrared light transmission level and a visible light reflectance level, the near-infrared transmission level being at least 50% independent of polarization of the near-infrared light.
2. The rearview assembly according to claim 1 , wherein the near-infrared light transmission level is at least 80%.
3. The rearview assembly according to claim 2 , wherein the visible light reflectance level is about 45%.
4. The rearview assembly according to claim 1 , further comprising:
a light source directed toward the fourth surface and configured to transmit the near-infrared light through the electrochromic element.
5. The rearview assembly according to claim 1 , wherein the transflective film is an anisotropic polymer-based film.
6. The rearview assembly according to claim 5 , wherein the transflective film includes at least 50 layers, wherein a consecutive pair of the at least 50 layers has different refractive indices.
7. The rearview assembly according to claim 1 , wherein the first surface corresponds to a viewing side of the rearview assembly and the fourth surface is directed into a housing of the rearview assembly.
8. The rearview assembly according to claim 1 , further comprising:
a metallic layer having a visible light reflectance level greater than the visible light reflectance level of the transflective film.
9. The rearview assembly according to claim 8 , wherein the metallic layer is disposed on the fourth surface between the second substrate and the transflective film.
10. The rearview assembly according to claim 1 , wherein the object is an eye of a user, and further wherein the near-infrared light reflected off the object is processed by a controller configured to determine an identity of the user based on the near-infrared light.