TIR light valve
View Patent ↗An array of light valves switch light by enabling and disabling total internal reflection (TIR) on a surface of the light valve. The disabling of the TIR is accomplished by putting another optical element in contact with the surface and then diffusing or changing the direction of the light. The mechanical mechanism to move the optical element is a simple one in that it only moves the optical element a small distance to change the valve from a first position to a second position.
1. A light valve device, comprising:
an array of light valves, at least one of the light valves comprising:
a light bending structure comprising a first surface, a second surface, and a third surface arranged such that light incident on the first surface of the light bending mechanism is internally reflected at the second surface of the light bending mechanism;
a switch element comprising a first surface, and a serrated second surface opposite the first surface; and
a moving mechanism to move the switch element relative to the second surface of the light bending structure,
wherein, when the switch element is in a first position, light incident on the first surface of the light bending structure internally reflects at the second surface of the light bending structure and passes through the third surface of the light bending structure, and
when the switch element is in a second position, the first surface of the switch element is in a position touching or in close proximity to the second surface of the light bending structure, so that light incident on the first surface of the light bending structure is not internally reflected at the second surface of the light bending structure, but rather continues on to the serrated second surface of the switch element, the serrated second surface directing the light in a direction different from a direction in which the light is reflected at the second surface of the light bending structure when the switch element is in the first position.
2. The light valve device of claim 1 , wherein the serrated second surface of the switch element reflects the light when the switch element is in the second position.
3. The light valve device of claim 1 , wherein the switch element absorbs the light when the switch element is in the second position.
4. The light valve device of claim 1 , wherein the switch element diffuses the light when the switch element is in the second position.
5. The light valve device of claim 1 , wherein the switch element has a diffuse topography so that the switch element does not direct the light to the third surface of the light bending structure when the switch element is in the second position.
6. The light valve device of claim 1 , wherein the light bending structure comprises a prism.
7. The light valve device of claim 1 , wherein the second surface of the light bending structure is coated with an elastic material to ensure that a gap between the light bending structure and the switch element is sufficiently narrow when the switch element is in the second position.
8. The light valve device of claim 1 , wherein the first surface of the switch element is coated with an elastic material to ensure that a gap between the light bending structure and the switch element is sufficiently narrow when the switch element is in the second position.
9. The light valve device of claim 1 , wherein an electrostatic force is used to move the switch element between the first position and the second position.
10. The light valve device of claim 1 , wherein a spring force is used to move the switch element between the first position and the second position.
11. The light valve device of claim 2 , wherein the serrated second surface comprises serrations angled such that the serrated second surface of the switch element and the second surface of the light bending structure reflect the light incident on the first surface of the light bending structure at different angles of reflection.
12. A projector, comprising the light valve device of claim 1 .
13. A display, comprising the light valve device of claim 1 .
14. A telecommunications system, comprising the light valve device of claim 1 .