High efficiency light transmitting window panel

• US 3,936,157 A
• Filed: 04/22/1974
• Issued: 02/03/1976
• Est. Priority Date: 04/22/1974
• Status: Expired due to Term

• Current Assignee: Kapany Corporation
• Original Assignee: Kaptron Incorporated
• Inventors: Kapany, Narinder S.
• Primary Examiner(s): Hayes, Monroe H.
• Application Number:
  US05/462,856
• Time in Patent Office: 652 Days
• Field of Search: 350/258, 350/259, 350/260, 350/261, 350/262, 350/263, 350/264, 350/265
• US Class Current: 359/591
• CPC Class Codes: F24S 10/00 Solar heat collectors using working fluids
• CPC Class Codes: F24S 80/50 Elements for transmitting incoming solar rays and preventing outgoing heat radiation; Transparent coverings
• CPC Class Codes: F24S 80/56 characterised by means for preventing heat loss
• CPC Class Codes: G02B 19/0019 having reflective surfaces only (e.g. louvre systems, systems with multiple planar reflectors)
• CPC Class Codes: G02B 19/0042 for use with direct solar radiation
• CPC Class Codes: Y02E 10/44 Heat exchange systems

Abstract

The window panel includes a plurality of sets of reflecting surfaces which are spaced apart from and facing each other and which transmit the incident light at least in part by multiple reflections. The sets of reflecting surfaces are arranged parallel to each other in a panel. In at least one embodiment the sets of opposed reflecting surfaces converge in the direction of incident light travel through the window panel and infrared reflecting means are provided to reflect infrared light attempting to pass through the window panel in a direction opposite to the direction of travel of the incident light.

Claims

1. A window panel comprising a pair of spaced apart transparent sheets, perpendicular supports for keeping the sheets spaced apart and for segmenting the air space between the sheets to prevent heat loss due to convective air currents, the supports being made of light transmitting material arranged to transmit incident light striking the window within a predetermined angle of acceptance through the window panel by means of multiple total internal reflections.

2. A window panel for use in a hollow structure for transmitting incident light into the interior of the structure comprising a plurality of opposed reflecting surfaces arranged in a panel for transmitting the incident light into the structure by multiple reflections, the panel of reflecting surfaces including a first set of elongated, parallel, triangularly shaped, reflectively surfaced wedges, each wedge having three apexes with one apex pointing in the direction toward the incident light, means for supporting the wedges so that the two apexes of each wedge which are opposite to the one apex are spaced apart from the corresponding apexes of adjacent wedges to thereby define a plurality of truncated, V-shaped, reflective surface channels, and infrared reflecting means disposed adajcent to the two opposite apexes of each wedge for reflecting back infrared light emitted from within the structure.

3. A window panel as recited in claim 2 wherein the first set of wedges are made of a light transmitting material and further comprising a second set of truncated, triangularly shaped wedges oriented in the opposite direction to the first set of wedges and interspersed between them, the second set of wedges being made of a light transmitting material having a higher refractive index than the material of the first set of wedges so that the interfaces between the wedges of the first and second sets form the plurality of V-shaped reflective surface channels.

4. A window panel as recited in claim 2 wherein the reflective surfaces of the wedges comprise multiply layered all dielectric coatings.

5. A window panel as recited in claim 2 wherein the reflective surfaces of the wedges comprise multiply layered metal-dielectric coatings.

6. A window panel for use in a hollow structure for transmitting incident light into the interior of the structure comprising a plurality of opposed reflecting surfaces arranged in a panel for transmitting the incident light into the structure by multiple, total internal reflections, the panel of reflecting surfaces including a parallel set of truncated, triangularly shaped wedges, each wedge having three apexes with one apex pointing in the direction away from the incident light, means for supporting the wedges so that the one apex of each wedge is spaced apart from the corresponding apex of adjacent wedges to thereby define a plurality of V-shaped channels, the wedges being made of a first light transmitting material, a second light transmitting material, of a lower refractive index than the refractive index of the first light transmitting material, the second light transmitting material filling the V-shaped channels such that reflective, dielectric surfaces which converge toward the interior of the structure are formed at the interfaces of the wedges and the second light transmitting material, the converging reflective surfaces serving to condense the bulk of the incident light so that is passes solely through the wedges.

7. A window panel as recited in claim 6 further comprising a pair of spaced apart transparent sheets and spaced apart support columns, arranged perpendicularly to the sheets, for keeping the sheets spaced apart, the supports being made of light transmitting material arranged to transmit incident light striking the window within a predetermined angle of acceptance through the window panel by means of multiple, total internal reflections.

8. A window panel as recited in claim 7 wherein the supports are in the shape of rods.

9. A window panel as recited in claim 7 wherein the supports are in the shape of honeycomb cells.

10. A window panel as recited in claim 7 further comprising means for segmenting air spaces between the sheets.