| 摘要 |
A radiant energy shade having a front panel of transparent sheet material pleated in parallel pleats, and a planar rear panel of radio-chromic sheet material which is normally transparent, but which darkens on exposure to the rays from the source of radiation. The shade is installed with the pleats partially open and, defining with the rear panel, triangular cross sections, preferably with the base side of each pleat extending at 90 DEG to the plane of the rear panel and with the other side oblique to the plane of the rear panel. The oblique sides are coated with opaque reflective material for their full length from the forwardmost edge part way toward the plane of the rear panel to provide show areas. The parallel base sides of the pleats and the remaining portions of the oblique sides are left clear. At higher levels of the source or sun, all of the direct rays are reflected forwardly by the coated show areas, while the shaded areas of the front panel and of the rear panel remain clear. At lower levels of the sun some rays do not strike the show areas, but strike and pass through the clear or shade areas of the front panel, striking areas of the rear panel which thereupon darken, thus excluding direct rays at lower sun levels.
|
