Light modulation device

A light modulation device, comprising:

• an active liquid crystal film layer;
• and
• a reflective layer,
• wherein the active liquid crystal film layer comprises:
• a first polymer film substrate;
• a second polymer film substrate;
• and
• an active liquid crystal layer disposed between the first and second polymer film substrates, wherein the active liquid crystal layer contains a liquid crystal host and a dichroic dye guest,
• wherein the active liquid crystal layer is capable of switching between a first orientation state and a second orientation state different from the first orientation state upon application of a voltage,
• each of the first and second polymer film substrates has an in-plane retardation of 4,000 nm or more for light having a wavelength of 550 nm,
• wherein each of the first and second polymer film substrates are stretched films, wherein the stretched films having a machine direction, a transverse direction, and a third direction, wherein the machine direction is perpendicular to the transverse direction, wherein an angle between the third direction and both the transverse direction and the machine direction ranges from 40 degrees to 50 degrees,
• wherein the machine direction, the transverse direction, and the third direction are in-plane directions,
• wherein the first and second polymer film substrates have an elongation (E1) in the transverse direction and an elongation (E2) in the machine direction,
• wherein each of the first and second polymer film substrates have an elongation (E3) in the third direction that is larger than E1, wherein a ratio of E3 to E2 is 5 or more, and
• wherein an angle formed by the transverse direction of the first polymer film substrate and the transverse direction of the second polymer film substrate is in a range of 0 degrees to 10 degrees.