Film-to-glass switchable glazing
A privacy glazing structure may include an electrically controllable optically active material, such as a liquid crystal material, sandwiched between a flexible substrate and a rigid substrate. The flexible substrate and the rigid substrate may each have a conductive layer deposited on the surface facing the optically active material. The flexible substrate may be bonded about its perimeter to the rigid substrate and may be sufficiently flexible to conform to non-planarity of the rigid substrate. As a result, the flexible substrate may adopt the surface contour of the rigid substrate to maintain a uniform thickness of optically active material between the flexible substrate and the rigid substrate.
1. A privacy glazing structure comprising:
a first rigid substrate of transparent material;
a second rigid substrate of transparent material that is generally parallel to the first rigid substrate, the second rigid substrate having a first surface and a second surface opposite the first surface;
a tubular spacer positioned between the first rigid substrate and the second rigid substrate to define a between-pane space;
a flexible substrate having a first surface and a second surface opposite the first surface;
a first substantially transparent conductive layer carried on the first surface of the flexible substrate;
a second substantially transparent conductive layer carried on the first surface of the second rigid substrate facing the between-pane space; and
an electrically controllable optically active material,
wherein the flexible substrate is bonded about its perimeter to the first surface of the second rigid substrate to form a cavity therebetween,
the electrically controllable optically active material is disposed within the cavity, and
the flexible substrate is sufficiently flexible to conform to non-planarity of the second rigid substrate.
2. The structure of claim 1 , wherein the flexible substrate is a polymeric sheet.
3. The structure of claim 2 , wherein the polymeric sheet comprises one or more layers formed of polyethylene terephthalate.
4. The structure of claim 1 , wherein the flexible substrate is aluminosilicate glass or borosilicate glass.
5. The structure of claim 1 , wherein the flexible substrate exhibits a flexural rigidity less than 5 N-mm.
6. The structure of claim 1 , wherein the flexible substrate exhibits a T 380 less than 2 percent.
7. The structure of claim 1 , wherein the second rigid substrate is tempered float glass.
8. The structure of claim 1 , wherein the second rigid substrate has a thickness ranging from 2 mm to 4 mm.
9. The structure of claim 1 , wherein the flexible substrate has a coefficient of thermal expansion, the second rigid substrate has a coefficient of thermal expansion, and the coefficient of thermal expansion of the flexible substrate ranges from 20 percent of the coefficient of thermal expansion of the second rigid substrate to 120 percent of the coefficient of thermal expansion of the second rigid substrate.
10. The structure of claim 1 , wherein the first substantially transparent conductive layer and the second substantially transparent conductive layer form opposite wall surfaces of the cavity.
11. The structure of claim 1 , further comprising a third rigid substrate laminated to the second surface of the second rigid substrate.
12. The structure of claim 1 , wherein the electrically controllable optically active material is a liquid crystal material having a light transmittance that varies in response to application of an electrical field.
13. The structure of claim 1 , wherein the electrically controllable optically active material is selected from the group consisting of an electrochromic material and a suspended particle material.
14. The structure of claim 1 , wherein the second rigid substrate has a compressive strength of at least 8,000 pounds per square inch.