US3471221A

US3471221A - Optical control of sunlight at window openings with a directionally selective,transparent sunshade to eliminate glaring sunlight rays while providing normal daylight illumination at windows

Info

Publication number: US3471221A
Application number: US499175A
Authority: US
Inventors: Bernard I Seeger
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-10-21
Filing date: 1965-10-21
Publication date: 1969-10-07
Anticipated expiration: 1986-10-07

Description

Oct. 7, 1969 B. I. SEEGER 3,471,221

OPTICAL CONTROL OF SUNLIGHT AT WINDOW OPENINGS WITH A DIRECTIONALLY SELECTIVE, TRANSPARENT SUNSHADE TO ELIMINATE GLARING SUNLIGHT RAYS WHILE PROVIDING NORMAL DAYLIGHT ILLUMINATION AT wmnows Filed 0ct.'2 l. 1965 ELYTLR BERNARD 1. 555619,?

6&3. BY v A TTOAPA/E V United States Patent US. Cl. 350-263 3 Claims ABSTRACT OF THE DISCLOSURE At building openings and elsewhere where glaring sunlight control is needed, multiple prism slats made of transparent material are rotatively positioned adjacent one another as a blind, and the slats are moved as the sun moves to intercept glare rays from the sun as respective sunlight glare rays enter respective thin wedge transport slats to be internally trapped through progressing slat interior deflections, as nonglare sunlight rays illuminate the space beyond the transparent blind.

This invention relates to transparent material assemblies used to arrest direct sun glare and heat, while affording minimal interference with daylight illumination and outward visibility in other directons. More particularly in the illustrated embodiment, such an assembly comprises transparent materials arranged as horizontal slats of a conventional venetian blind, although the slat arrangement may alternatively be vertical.

The purpose of the invention is to control sunlight and its glare effects with transparent material assemblies which at all times continue to pass sufiicient quantities of indirect daylight for continued active use of space beyond any slat assembly without having to resort to artificial lighting.

The invention, briefly described in reference to an illustrated embodiment comprises horizontal blind arrangements of multiple slats which are collectively moved and positioned to intercept as many as possible of the glare rays from the sun, with each slat being a thin wedge and preferably having its thick edge V-grooved with all surfaces being smooth.

The invention is illustrated in the accompanying drawings, wherein FIGURE 1 is a perspective partial sectional view of a window in a home or office with a horizontal blind of transparent material arranged in a working position;

FIGURE 2 is an enlarged end view of the transparent material made into a thin wedge slat, showing in dotted lines a typical optical path of an accepted and desirable nonglare light ray; and

FIGURE 3 is an enlarged end view of the transparent material similar to FIGURE 2, showing in dotted lines the optical path of a glaring sunlight ray internally trapped and dissipated through successive total reflections.

Referring to FIGURE 1, the illustrated embodiment of this invention provides horizontal blinds 12 of transparent materials 14 to optically control sunlight at window or like openings 16. The materials used are highly transparent to all visible light. However, these materials are generally shaped as indicated in FIGURES 2 and 3 to trap the glaring sun rays and their heat energy.

In reference to the utilization of a transparent polymethyl methacrylate material, having a refractive index ice of 1.49, a preferred construction of a slat 22 is shown in FIGURES 2 and 3. A thin wedge shape is used with a loading pointed edge 24 nearest the opening 16 having an apex angle which determines the size of the following slowly widening transparent body which terminates in a thicker edge 26 that is V-grooved 28. All the surfaces of the thin wedge slat 22 are smooth throughout its length which is determined by the width of the opening 16, The optimum apex angle of these transparent slats depends upon the refractive index of the slat material, as well as upon stowage considerations in retracting the blind from its functional deployment.

The multiple arrangement of these slats 22 may be undertaken by some of the ways already known where they are preferably held and rotated by slat end mounting devices, not shown. The slat suspension and positioning controls, not shown, will maintain a common attitude of all slats 22 to trap the glare rays which may be coming directly from the sun, reflected from a water surface, glass surface of an adjacent building, etc.

The successful control of sunlight or other glare rays of extreme intensity and the simultaneous passage of less intense and indirect light is illustrated in FIGURES 2 and 3. The slat 22, enlarged over FIGURE 1, as shown in FIGURE 2 is receivinga less intense light ray B which it passes to provide diffused daylight lighting in an interior space. In FIGURE 3, however, slat 22 is receiving an intense direct sun ray A which it traps during several interior total deflections. Such entrapment is made even more effective by the presence of the V-groove 28 in its edge 26.

It will be realized that what has been separately illustrated in FIGURES 2 and 3, is actually occurring simultaneously as light rays pass into each slat 22 of the blind 12 to be selectively optically directed to achieve the purpose of the invention to provide daylight illumination and outward visibility without glare. During this selective optical direction of blind 12, the wedge points 24 of slats 22 are directed at or nor the position of the sun in operation of the blind.

I claim:

1. A transparent material assembly to optically control sunlight and its glare effects while providing outward visibility and continuing to pass suflicient quantities of daylight for continued active use of space beyond such transparent material assembly without having to resort to artificial lighting, comprising:

(a) conventional positioning devices adapted to hold and to pivot multiple prism slats of transparent material across an area at which glare rays of sunlight may be incident; and

(b) multiple prism slats, each of which is thin wedge shaped in cross section with its pointed edge oriented toward the direction of the sun, are fitted in part into the conventional positioning devices, for adjustment to prevent passage of glare rays of sunlight through the sunlight area.

2. A transparent material assembly to optically control sunlight, as claimed in claim 1, wherein each prism slat of wedge shape has its larger end recessed to further confine internally reflected light rays.

3. A transparent material assembly adapted for use at an opening in a structure to optically intercept glare effects of direct sunlight, while passing a sufficient level of diffused daylight to avoid recourse to artificial lighting, comprising:

(a) multiple parallel transparent prism slats, each of which is thin wedge shaped in cross section with its pointed edge oriented toward the direction of the 3 4 sun, to arrest visible and invisible solar radiations R f C1 d within a range of incidence angles that is relatively e erences e narrow, but broad enough to substantially exceed the UNITED STATES ATENTS angular subtense of the sun, and to pass desirable 719,065 1/1903 Wadsworth 350 263 and beneficial daylight within broad ranges of in- 5 1,937,342 11/1933 Higbie 350 263 cidence angles that are symmetrically disposed on either side of the narrower arresting range of visible FOREIGN PATENTS and invisible solar radiations; and 336,556 3/1904 France.

(b) conventional positioning devices adapted to hold and to pivot the multiple parallel transparent prism 10 JULIA E. COINER, Primary Examiner slats across an opening in a structure to keep them directionally selective to arrest the visible and in- US. Cl. X.R. visible solar radiations thereby eliminating the glare 350-465 while passing dilfused daylight.