Optical elements and systems for reflecting direct beam sunlight while admitting diffuse skylight through building apertures

Patent metadata

Field	Value
Publication number	US-12209719-B2
Application number	US-202118007130-A
Country	US
Kind code	B2
Filing date	Jul 27, 2021
Priority date	Jul 27, 2020
Publication date	Jan 28, 2025
Grant date	Jan 28, 2025

Abstract

Optical elements and systems are disclosed that can be incorporated into buildings to prevent beam sunlight from entering through apertures of the building while allowing diffuse skylight to enter the building through the apertures. The optical system comprises optical elements configured to admit diffuse skylight through an aperture in the building envelope, while reflecting away the beam sunlight incident on the aperture in the building envelope. The apertures can be, for example, windows in walls or skylights in roofs of the building envelope. The optical system works for both windows in the walls and skylights in the roof, with somewhat different configurations for those two parts of the building envelope.

First claim

What is claimed is:

1. An optical system for reflecting direct beam sunlight while admitting diffuse skylight through building apertures, the optical system being configured to be secured to a building aperture of a building, the optical system comprising:
at least a first optical element comprising at least a first sheet of optically transmissive material, said at least a first sheet having at least a first side and a second side, the first side facing away from the building, the second side facing an interior of the building, the second side having at least a first set of optical features formed therein that are designed to reflect beam sunlight away from the second side while passing diffusive light through the second side when the first optical element is in a first orientation relative to a Sun; and
a rotation-imparting mechanism mechanically coupled to said at least a first optical element, the rotation-imparting mechanism imparting rotational motion to said at least a first optical element to cause said at least a first optical element to track the Sun and remain in the first orientation relative to the Sun such that rays of beam sunlight are incident on optical features of the first set of optical features at a preselected angle of incidence that results in the optical features reflecting the rays of beam sunlight away from the second side while passing the diffuse light through the second side.

2. The optical system of claim 1 , wherein the optical features comprise an array of serrations formed in the second side and extending in a lengthwise direction that is substantially parallel to a plane in which the rays of beam sunlight propagate.

3. The optical system of claim 2 , wherein each serration has first and second inner sides that are at a preselected angle to one another.

4. The optical system of claim 3 , wherein the first sheet is divided into alternating offset strips of optical elements, wherein adjacent strips have vertical voids that are absent of the optical features such that diffuse light passes through the vertical voids.

5. The optical system of claim 4 , wherein the vertical voids are covered with vertical sheets of optically transmissive material, and wherein diffuse light passes through the vertical sheets.

6. The optical system of claim 5 , further comprising an internal glazing surface that is coupled to the vertical sheets such that still air is encapsulated in between the internal glazing surface, the vertical sheets and at least one of the first and second sides of the first sheet.

7. The optical system of claim 2 , wherein the optical system comprises an array of parallel optical-element slats, each optical-element slat comprising a plurality of the optical elements having serrations on one side, a long dimension of the optical-element slats being parallel to the serrations, and each optical-element slat being able to rotate about an axis parallel to the serrations.

8. The optical system of claim 1 , further comprising an external glazing surface, wherein said at least a first optical element works in conjunction with the external glazing surface to seal the building aperture and to encapsulate a still layer of air or other insulating gas to enhance a thermal integrity of the building aperture.

9. The optical system of claim 1 , further comprising an interior glazing surface, wherein said at least a first optical element works in conjunction with the internal glazing surface to seal the building aperture and to encapsulate a still layer of air or other insulating gas to enhance a thermal integrity of the building aperture.

10. The optical system of claim 9 , wherein the interior glazing surface is a flat surface or a curved surface having prismatic or diffusing elements formed therein for dispersing diffusive light around the interior of the building.

11. The optical system of claim 1 , wherein said at least a first optical element is rotated by the rotation-imparting mechanism about an axis that is perpendicular to the first sheet and located at a center of said at least a first optical element.

12. The optical system of claim 1 , wherein said at least a first optical element is a circular optical element and the building aperture is a circular aperture, and wherein the circular optical element fully protects the circular aperture against all incoming beam sunlight.

13. The optical system of claim 1 , wherein said at least a first optical element is a circular optical element and the building aperture is a non-circular aperture, and wherein the circular optical element partially protects the non-circular aperture against incoming beam sunlight, while allowing beam sunlight to penetrate through unprotected parts of the non-circular aperture lying outside the circular optical element.

14. The optical system of claim 1 , further comprising one or more surfaces for a low-E coating to help suppress thermal radiation transfer through a glazing assembly of the building aperture.

15. The optical system of claim 1 , wherein the rotation-imparting mechanism is controlled to admit at least some amounts of beam sunlight into the interior of the building.

16. The optical system of claim 1 , wherein the optical system comprises an optical-element sunshade system comprising a plurality of optical elements coupled to separate mounts that are rotated by the rotation-imparting mechanism.

17. The optical system of claim 16 , wherein the optical-element sunshade system comprises a plurality of highly reflective surfaces, where adjacent highly reflective surfaces are separated from one another by daylight apertures that are covered with insulated glazing surfaces, and wherein diffuse skylight that is not incident on the optical elements passes through the insulated glazing surfaces and the daylight apertures into the interior of the building, and wherein beam sunlight that is not incident on the optical elements is incident on the plurality of highly reflective surfaces and is reflected by the plurality of highly reflective surfaces.

18. The optical system of claim 17 , further comprising a protective exterior, the optical-element sunshade system being configured to be installed on a ceiling of the building.

19. The optical system of claim 16 , wherein the optical-element sunshade system is configured for a circular aperture, and wherein the rotation-imparting mechanism comprises an Equatorial Mount to adjust a location of the optical-element sunshade system to shade the building aperture and to adjust an orientation of the optical-element sunshade system relative to the Sun based on a time of year so that a normal to a plane of the optical-element sunshade system points toward the Sun.

20. The optical system of claim 19 , wherein the optical-element sunshade system slides along an Arc Beam to account for seasonal changes in a position of the Sun and rotates about an axis parallel to an Earth's rotational axis to account for diurnal changes in the position of the Sun.

Assignees

• Univ North Carolina State

Inventors

• Place Jeffrey Wayne

Classifications

• F21V5/02

  of prismatic shape (F21V5/04 takes precedence) · CPC title

• E06B2009/2417

  Light path control; means to control reflection · CPC title

• E06B9/24

  Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; {Slat blinds}(operating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00) · CPC title

• E04D13/0357

  the parts pivoting about an axis supported on a hinged frame or arms · CPC title

• E04D13/0354

  the parts being flat · CPC title