Patent ID: 8296994

Claim:
A greenhouse comprising: a support frame including a cover unit; and a film sheet at least partially covering the cover unit, wherein the film sheet includes a film and a first plurality of prism assemblies arranged on the film to neighbor each other, wherein a selected one prism assembly of the first plurality of prism assemblies includes (a) a first prism unit including a plurality of first prisms with slanted angles that are substantially the same as each other, and (b) a second prism unit neighboring the first prism unit and including a plurality of second prisms with slanted angles that are substantially the same as each other, wherein the film sheet includes a second plurality of prism assemblies arranged on an opposite side of the film with respect to the first plurality of prism assemblies, wherein a selected one prism assembly of the second plurality of prism assemblies includes (a) a third prism unit including a plurality of third prisms with slanted angles that are substantially the same as each other, and (b) a fourth prism unit including a plurality of fourth prisms with slanted angles that are substantially the same as each other, wherein a width of the first prism unit and a width of the second prism unit are substantially the same, wherein the slanted angles of the plurality of first prisms are different from the slanted angles of the plurality of second prisms, wherein the slanted angles of the plurality of third prisms are different from the slanted angles of the plurality of fourth prisms, wherein the film sheet includes a first cover film at least partially covering the first plurality of prism assemblies with a substantially planar surface, and wherein the film sheet includes a second cover film at least partially covering the second plurality of prism assemblies with a substantially planar surface, and wherein the first plurality of prism assemblies are positioned on the film sheet so as to produce alternating elongate regions of shadow and elongate regions of focused light on a floor region of the greenhouse when the greenhouse is exposed to sunlight.