Natural-light illumination enhancement assembly

• US 4,634,222 A
• Filed: 06/15/1984
• Issued: 01/06/1987
• Est. Priority Date: 06/17/1983
• Status: Expired due to Fees

• Current Assignee: National Research Development Corporation
• Original Assignee: National Research Development Corporation
• Inventors: Critten, Donald L.
• Primary Examiner(s): WINTERCORN, RICHARD
• Application Number:
  US06/620,925
• Time in Patent Office: 935 Days
• Field of Search: 350/258-265
• US Class Current: 359/596
• CPC Class Codes: A01G 9/243 Collecting solar energy in general F24S
• CPC Class Codes: E06B 2009/2417 Light path control; means to control reflection
• CPC Class Codes: E06B 9/386 Details of lamellae
• CPC Class Codes: F21S 11/00 Non-electric lighting devices or systems using daylight roofs with sky-light opening E04D13/03; sun blinds for windows with means for redirecting light onto ceiling of a room E06B9/00; hybrid lighting devices combining artificial and natural light F21S19/00; solar heat collectors F24S; solar cells or solar cell modules H01L31/00
• CPC Class Codes: Y02A 40/25 Greenhouse technology, e.g. cooling systems therefor
• CPC Class Codes: Y02P 60/12 using renewable energies, e.g. solar water pumping

Abstract

A louvred reflector 10 (FIG. 1) comprises an array of wholly or partially reflecting louvres of which two adjacent louvres 12,13 are shown in the Figure. Each said louvre, when viewed short-edge on as shown in the Figure, comprises an inclined downwardly-facing concave first section 15 and a lower, less-steeply inclined, downwardly-facing concave second section 16. Light reflected by the louvres is downwardly directed over a considerable angular range to produce generally uniform illumination on either side of the reflector. In a second embodiment, the reflected light is directed to only one side of the reflector.

Claims

1. A natural-light illumination enhancement assembly, comprising:

a louver array including at least on louver;

each louver of said array having means defining an at least partially-reflective lower surface;

means mounting all of said louvers so as to have direct sunlight incident upon at least some of said at least partially reflective lower surface of each and for mounting each of said louvers in such relation to one another that at least some of said incident direct sunlight is reflected by each of said louvers from said at least partially reflective lower surface thereof to a notional plane disposed at a lower level than said louver array;

each of said at least partially reflecting louvers, when viewed short-edge on, comprising an inclined downwardly-facing concave first section and a lower downwardly-facing concave second section which is less-steeply inclined than the first section and having about double the length of the first section when so viewed, both the first and the second sections lying on or close to respective 15°

circular arcs and meeting one another at about 145°

to define a downwardly-facing ridge-like portion, the vertical separtion of like parts of adjacent said louvers being about half the edge-to-edge dimensions of each said louver when so viewed.

2. An assembly as claimed in claim 1 in which one or other or both of the two sections has a curvature of other than 15°

or is straight when viewed short-end on.

3. An assembly as claimed in claim 1 in which the louvres are mounted in such a way as to allow their orientations to be varied to suit different lighting situations.

4. An assembly as claimed in claim 1 in which each said at least partially reflecting louver blade is of about 0.2 mm material thickness, has a long-side length of about 3 meters and has a short-side length dimension of about 5 cm.

5. A natural-light illumination enhancement assembly, comprising:

a louver array including at least one louver;

each louver of said array having means defining an at least partially-reflective lower surface;

means mounting all of said louvers so as to have direct sunlight incident upon at least some of said at least partially reflective lower surface of each and for mounting each of said louvers in such relation to one another that at least some of said incident direct sunlight is reflected by each of said louvers from said at least partially reflective lower surface thereof to a notional plane disposed at a lower level than said louver array;

each of said at least partially reflecting louvers, when viewed short-edge on, comprising an inclined downwardly-facing straight or slightly concave first section merging tangentially into a lower inclined downwardly-facing concave second section of significantly greater curvature than the first section and of about double the length of the first section when so viewed, the second section lying on or close to a 15°

circular arc and the vertical separation of like parts of adjacent said louvers being about half the edge-to-edge dimension of each said louver when so viewed.

6. A natural-light illumination enhancement assembly, comprising:

a louver array including at least one louver;

each louver of said array having means defining an at least partially-reflective lower surface;

means mounting all of said louvers so as to have direct sunlight incident upon at least some of said at least partially reflective lower surface of each and for mounting each of said louvers in such relation to one another that at least some of said incident direct sunlight is reflected by each of said louvers from said at least partially reflective lower surface thereof to a notional plane disposed at a lower level than said louver array;

each of said at least partially reflecting louvers, when viewed short-edge on, comprising an inclined downwardly-facing first section pivotally connected to a downwardly-facing concave second section, the second section lying on or close to a 15°

circular arc, when so viewed, and the first section being straight or lying on a second circular arc of the same or lesser curvature than the arc for the first section and the vertical separation of like parts of adjacent said louvers being about half the edge-to-edge dimension of each said louver when so viewed.

7. A natural-light illumination enhancement assembly, comprising:

a louver array including at least one louver;

each louver of said array having means defining an at least partially-reflective lower surface;

means mounting all of said louvers so as to have direct sunlight incident upon at least some of said at least partially reflective lower surface of each and for mounting each of said louvers in such relation to one another that at least some of said incident direct sunlight is reflected by each of said louvers from said at least partially reflective lower surface thereof to a notional plane disposed at a lower level than said louver array;

said louvers being mounted in such a way as to allow their orientations to be varied to suit different lighting conditions;

said louvers being controlled by a microprocessor or small computer to vary the louver inclination to produce a more even overall illumination or to reflect more or less light to one or another side of said at least partially reflective surface thereof.

8. A natural-light illumination enhancement assembly, comprising:

a louver array including at least one louver;

each louver of said array having means defining an at least partially-reflective lower surface;

means mounting all of said louvers so as to have direct sunlight incident upon at least some of said at least partially reflective lower surface of each and for mounting each of said louvers in such relation to one another that at least some of said incident direct sunlight is reflected by each of said louvers from said at least partially reflective lower surface thereof to a notional plane disposed at a lower level than said louver array;

at least some of said louvers being constructed of a partially reflecting material in situations where a lower louver may partially obscure its immediate upper neighbour or where, if a gap were left to avoid this, there would be a chance of light passing straight through this gap.

9. A natural-light illumination enhancement assembly comprising:

a greenhouse extending along an east-west axis, and having a south-facing wall adapted to admit direct sunlight throughout a substantial portion of the year;

a louver array including at least one louver;

each louver of said array having means defining an at least partially-reflective lower surface;

means mounting all of said louvers in said greenhouse so as to have direct sunlight incident upon at least some of said at least partially reflective lower surface of each and for mounting each of said louvers in such relation to one another that at least some of said incident direct sunlight is reflected by each of said louvers from said at least partially reflective lower surface thereof to a notional plane disposed at a lower level than said louver array;

each of said at least partially reflecting louvers, when viewed short-edge on, comprising an inclined downwardly-facing concave first section and a lower downwardly-facing concave second section which is less-steeply inclined than the first section and having about double the length of the first section when so viewed, both the first and the second sections lying on or close to respective 15°

circular arcs and meeting one another at about 145°

to define a downwardly-facing ridge-like portion, the vertical separation of like parts of adjacent said louvers being about half the edge-to-edge dimensions of each said louver when so viewed; and

an array of plants growing in said greenhouse at said level and being illuminated at least in part, by sunlight reflected directly onto them from said lower surfaces of said reflectors.