System and eyewear for viewing stereoscopic imagery
View Patent ↗A super-twist nematic (STN) liquid crystal (LC) light shutter with improved contrast performance, lower power requirements and enhanced off-axis performance. Compensator components may be disposed in front of and, in some cases, behind the liquid crystal cell. In some embodiments, a STN LC cell with a twist angle of 270 degrees may be used. In other embodiments, a STN LC cell with a twist angle ranging between just greater than 270 degrees and 285 degrees may be used. Also disclosed is a system incorporating the various disclosed STN LC shutters.
1. A liquid crystal shutter lens, comprising:
a first polarizer having an absorption axis oriented in a first direction;
a second polarizer having an absorption axis oriented in a second direction and substantially orthogonal to the first direction;
a super-twisted nematic (STN) liquid crystal (LC) cell positioned between the first polarizer and the second polarizer, wherein the STN LC cell has a first buffing direction, and wherein the STN LC cell has a second buffing direction substantially 270 degrees from the first direction;
a first compensator element between the first polarizer and the second polarizer, wherein the first compensator element is a first biaxial compensator, wherein the first biaxial compensator element is between the first polarizer and the STN LC; and
a second biaxial compensator element between the second polarizer and the STN LC, wherein the second biaxial compensator has a slow axis oriented at an angular range of zero to ten degrees relative to the absorption axis of the second polarizer.
2. The liquid crystal shutter lens of claim 1 , wherein the first biaxial compensator has a slow axis oriented at an angular range of zero to ten degrees relative to the absorption axis of the first polarizer.
3. The liquid crystal shutter lens of claim 1 , wherein the first biaxial compensator has a slow axis parallel to the absorption axis of the first polarizer.
4. Eyewear for viewing stereoscopic content, comprising:
a first shutter lens comprising:
a first polarizer axis having an absorption axis oriented in a first direction;
a second polarizer having an absorption axis oriented in a second direction and substantially orthogonal to the first direction;
a first super-twisted nematic (STN) liquid crystal (LC) cell positioned between the first polarizer and the second polarizer, wherein the first STN cell has a first buffing direction, and wherein the first STN LC cell has a second buffing direction substantially 270 degrees from the first direction;
a first biaxial compensator element between the first polarizer and the first STN LC cell;
a second biaxial compensator element between the second polarizer and the first STN LC cell;
a second shutter lens comprising:
a third polarizer having an absorption axis oriented in a third direction;
a fourth polarizer having an absorption axis oriented in a fourth direction and substantially orthogonal to the third direction;
a second super-twisted nematic (STN) liquid crystal (LC) cell positioned between the third polarizer and the fourth polarizer, wherein the second STN LC cell has third buffing direction, and wherein the second STN LC cell has a fourth buffing direction substantially 270 degrees from the third direction;
a third biaxial compensator element between the third polarizer and the second STN LC cell; and
a fourth biaxial compensator element between the fourth polarizer and the second STN LC cell.
5. The eyewear of claim 4 , wherein the first buffing direction is oriented in substantially the same direction as the first direction, and wherein the third buffing direction is oriented in substantially the same direction as the third direction.
6. The eyewear of claim 4 , wherein the first buffing direction is oriented substantially perpendicular to the first direction, and wherein the third buffing direction is oriented substantially perpendicular to the third direction.
7. The eyewear of claim 4 , further comprising a controller communicatively coupled to the first and second shutter lenses.
8. A liquid crystal shutter lens, comprising:
a first polarizer having an absorption axis oriented in a first direction;
a second polarizer having an absorption axis oriented in a second direction and substantially orthogonal to the first direction;
a super-twisted nematic (STN) liquid crystal (LC) cell positioned between the first polarizer and the second polarizer, wherein the STN LC cell has a first buffing direction, and wherein the STN LC cell has second buffing direction greater than 270 degrees from the first direction;
a first compensator element located between the STN LC cell and the first polarizer, the first compensator element having a slow axis oriented in a third direction, wherein the third direction is in a range of zero to ten degrees from the first direction.
9. A liquid crystal shutter lens, comprising:
a first polarizer having an absorption axis oriented in a first direction;
a second polarizer having an absorption axis oriented in a second direction and substantially orthogonal to the first direction;
a third polarizer having an absorption axis oriented substantially parallel to the first direction; and
a super-twisted nematic (STN) liquid crystal (LC) having a twist angle of substantially 275 degrees.