US3668381A - Prismatic light louver - Google Patents

Prismatic light louver Download PDF

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Publication number
US3668381A
US3668381A US7950A US3668381DA US3668381A US 3668381 A US3668381 A US 3668381A US 7950 A US7950 A US 7950A US 3668381D A US3668381D A US 3668381DA US 3668381 A US3668381 A US 3668381A
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United States
Prior art keywords
louver
prisms
membrane
cell
set forth
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Expired - Lifetime
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US7950A
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English (en)
Inventor
Robert A D Schwartz
Rodney P Osterberg
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Individual
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V3/00—Globes; Bowls; Cover glasses
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V5/00—Refractors for light sources
    • F21V5/02—Refractors for light sources of prismatic shape
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2103/00—Elongate light sources, e.g. fluorescent tubes

Definitions

  • louver for use as a ceiling panel in a luminous ceiling or as a lens in a lighting fixture.
  • the louver has 1 12 Claim, 5 Drawing Figures PATENTEnJun 6 I972 3, 668 381 1 RODNEY OSTERBERG ATTORN EY PRISMATIC LIGHT LOUVER BACKGROUND OF THE INVENTION
  • PATENTEnJun 6 I972 3, 668 381 1 RODNEY OSTERBERG ATTORN EY PRISMATIC LIGHT LOUVER BACKGROUND OF THE INVENTION In the lighting industry it has been previously suggested that certain advantages are present in the use of a closed cell translucent panel.
  • Positioning sucha panel subjacent the light source generally conceals the plenum and shields thelight source from direct vision, with the solid membrane or'top wall thereof serving as a diffuser to reduce reflected glare and the cell walls shadowed to reduce direct glare.
  • Lighting panels of this general nature are described, for example, in Schwartz et al. U.S. Pat. No. 3,368,070. Notwithstanding advantages-inherent in such a closed cell system, certain shortcomings are also presentI'Primarily, it is found that if sufficient light is transmitted through the panel or lighting louver to provide adequate illumination on the work surface or for general lighting requirements, undesirable high level brightness is also present. In other words, when a person views such-an overhead horizontally disposed panel at a high angle from the vertical, the overall ceiling effect produces a relatively harsh glare.
  • the present invention is directed towards a closed cell louver system which is modified soas to produce a maximum of light at low angles from the vertical, i.e., for maximum illumination at a work surface, and a minimum of light at high angles from the vertical so as to reduce the overall glare effect accompanying high level brightness.
  • the invention includes the use of prisms for each cell which are so arranged that maximum light transmission efficiency is obtained while high level brightness is minimized.
  • the cross: sectional configuration of the respective prisms is asymmetri cal or possesses a saw-tooth shape, with the prisms extending concentric or parallel to the cell wall.
  • the overall effect of such a prismatic light louver is the provision of a high efficiency lens which cuts out high level brightness, as will be hereinafter discussed in more detail.
  • FIG. I is a plan view of a portion of a prismatic light louver of the present invention.
  • FIG. 2 is a plan view on an enlarged scale showing-four adjacent cells of the louver
  • FIG. 3 is a cross-sectional view of one cell on a further enlarged scale, taken substantially in the plane indicated by line 3-3 of FIG. 2;
  • FIG. 4 is a further enlarged view of a portion of the prism structure shown in FIG. 3;
  • FIG. 5 is a plan view of a single cell of a modified form of cell and prism arrangement.
  • the panel or louver of the present invention is of generally planar configuration and adapted to be positioned adjacent a light source.
  • the edges of the-panels are not panel can be of any desired length, width or planar shape, and where used as the lens of a lighting fixture will usually be formed as a single integral piece.
  • a plurality of separate panels may be interconnected to provide an overlapping and interlocking continuous appearing modular ceiling in the manner disclosed in the aforesaid U.S. Pat. No. 3,368,070.Since the manner of interconnecting adjacent'panels fonns no part of the present invenillustrated nor described herein.
  • the panel is formed of a suitable plastic material, such as acrylic, by injection molding or the like, and includes a flat rigid and form retaining planar membrane or wall 12 having an upper surface 14 and a lower surface 16.
  • a plenum or light source is disposedin overlying relation to the upper surface 14 and surface 16.
  • each cell 18 consists of an annular wall 20 which, with the adjacent pora person within a room would see the lower tion of surface 16, defines a downwardly directed cell area 22.
  • each cell is provided with prisms, generally indicated at 28. As here illustrated, such prisms are provided on lower surface 16 of membrane 12," but it is possible that the same could be disposed on the upper surface-l4. In practice, however, it has been found thatit is easier to polishtheprismswhen disposed within the cell rather than on the continuous upper surface of the panel. It will be noted of each cell,'the interstice portions 24 being preferably nonprismatic.
  • the configuration of the prisms and their relationship to the cell walls 20 constitute an important feature of the present invention. Basically, what is desired is a lightdistribution pattern through the prisms so that a maximum amount of light is directed downwardly between each cell wall 20, and a minimum amount of light will be directed past and under the bottom edge 34 0f the cell wall at a small acute angle with the plane of the panel. With such an arrangement, the prisms will provide a shield against direct glare for' a person looking directly upwardly towards the panel and a shielding of the plenum chamber and light source. Further, the prisms, in combination with the cell walls, minimize high level brightness. Finally, and as will be shortly explained, these desirable features are attained with maximum lighting efficiency for a prismatic light control system.
  • the prisms 28 are of a sawtooth or asymmetrical cross-sectional configuration as best seen in FIGS. 3 and 4, but the length of the prisms are symmetrical relative to the shielding means, i.e., the cell wall 20, as best illustrated in FIG. 2 of the drawing.
  • the shielding means i.e., the cell wall 20, as best illustrated in FIG. 2 of the drawing.
  • six continuous prisms are provided in each cell, designated as P1, P2, P3, P4, P5 and P6, each concentric about the cell axis and parallel to the cell wall 20.
  • the exact number of prisms is not critical, but the spacing between adjacent prisms results in a substantially continuous prismatic surface, and as here illustrated, such spacing approximates the thickness of membrane 12.
  • the prisms are relatively shallow in depth and preferably have a depth dimenpattern with maximum efficiency,the inner prism surface 38 defines a larger included angle with the vertical than does the angle defined by the outer prism surface 40 with the vertical line being taken at the intersection of the respective prism surfaces with the lower surface 16 of panel 10.
  • a particularly effective arrangement has been produced where the inner surface 38 defines an angle of about 50 with the vertical and the outer surface defines an angle of about with the vertical.
  • inner prism surface is used herein to define the prism surface facing the axial center line of the cell, while the term outer prism surface” refers to the other prism surface or the one facing the interior of its cell wall 20.
  • the prism surfaces 40 facing such wall are only offset by' about. 10 from being parallel therewith, while the prism surfaces 38 form a substantial angle thereto.
  • the respective surfaces 38 and 40 l of each prism intersect and terminate along a lower circular line 41, and the innermost surfaces of surfaces 38 and 40 of adjacent prisms terminate and intersectalong an upper circular line 42 on the lower surface 16 of the panel.
  • each prism it might be said that it comprises an acute irregular triangle in cross-section defined by surfaces 38 and 40 and the adjacent portion of membrane surface 16, but extends lineally in the symmetrical pattern above described,
  • the asymmetrical orientation of the prism surfaces is that as above described, i.e., with the more vertical prism surface 40 directed towards of facing the cell wall. Withthis arrangement, brightness at high angles is shielded by the adjacent cell wall. If such surface 40 was reversed, as the surface became brighter at high angles, the more distant cell wall would not be as efficient in producing the desired shielding.
  • FIG. 5 a modified form of cell structure is illustrated which in place of the circular cell wall is of square configuration having sidewalls 44, 46, 48 and 50. The depth of such walls would correspond to the depth of wall 20.
  • a plurality of prisms P7, P8, P9, P10, P11 and P 12 are provided, each prism being symmetrical about the central axis of the cell and having four lineally extending sides parallel to the respective cell walls.
  • the saw tooth prism construction is the same as previously described, and a cross-section taken through the center of the cell would be identical to the cross-sectional view of FIG. 3.
  • the louver above described lends itself to the production of a unique and ornamental two-color design.
  • the cell walls 20 and the interstice portions 24 may be frosted.
  • the polished prism will appear bright, while the cell walls and interstice portion, particularly when frosted, will pick up the color. Since substantially all of the usable light passes through the prisms, the tinting of the plastic will not materially'reduce the light transmission efficiency.
  • e cell walls will reduce high-level brightness, but not to the extent provided for by the saw tooth prism construction described above.
  • a light louver including a generally planar rigid membrane, wall means formed integ'rallywith said membrane and extending normal from one surface of said membrane and defining a plurality ofadjacent cells, each of said cells being 1 generally symmetrical about the central axis thereof, a surface of said membrane being provided with a plurality of prisms disposed within the peripheral confines of the respective cells, said prismatic portion of said membrane being polished, said wall means being frosted to thereby define a lusterless surface compared to said polished prismatic surface, said prisms extending lineally symmetrically about each cell axisand sym: metrically with the wall means defining the respective cell, and said prisms extending uniformly across substantially the entire peripheral extent of each cell.
  • each of said prisms has a pair of asymmetrical surfaces extending from a surface of said membrane.
  • a louver as set forth in claim 3 in which a plurality of said prisms are defined in adjacent concentric relation within each cell, and each of said prisms has a pair of asymmetrical surfaces extending from' the surface of said membrane from which said wall means extend.
  • a louver as set forth in claim 8 inwhich said lesser angle is about 10 and the first mentioned surface defines an angle of about 50 with said axis.
  • a louver as set forth in claim 5 in which said cells are substantially deeper than the depth of said prisms and extend a substantially greater distance from said membrane than said prisms.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Optical Elements Other Than Lenses (AREA)
  • Optical Measuring Cells (AREA)
US7950A 1970-02-02 1970-02-02 Prismatic light louver Expired - Lifetime US3668381A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US795070A 1970-02-02 1970-02-02

Publications (1)

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US3668381A true US3668381A (en) 1972-06-06

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US7950A Expired - Lifetime US3668381A (en) 1970-02-02 1970-02-02 Prismatic light louver

Country Status (5)

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US (1) US3668381A (enExample)
CA (1) CA920563A (enExample)
DE (2) DE7103780U (enExample)
FR (1) FR2079195B1 (enExample)
GB (1) GB1302648A (enExample)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3996458A (en) * 1974-02-25 1976-12-07 Jones Terry D Ceiling system
US4462068A (en) * 1982-06-24 1984-07-24 Manville Service Corporation Luminaire with improved lens structure
US4761641A (en) * 1983-01-21 1988-08-02 Vidcom Rentservice B.V. Information display system
US20060050200A1 (en) * 2004-08-26 2006-03-09 Fuji Photo Film Co., Ltd. Prism sheet and display device using the same
US20060187654A1 (en) * 2003-07-24 2006-08-24 Johannes Jungel-Schmid Ambient lighting system
US20070046874A1 (en) * 2005-08-12 2007-03-01 Masaya Adachi Display device and electrical appliance using the same
US20090016067A1 (en) * 2007-07-12 2009-01-15 Hon Hai Precision Industry Co., Ltd. Optical plate and backlight module using the same
US20100080007A1 (en) * 2008-09-29 2010-04-01 Ping-Han Chuang Light distribution board having improved grating structure including a plurality of light gratings each with multiple focuses
USD632421S1 (en) * 2010-06-02 2011-02-08 Star Headlight & Lantern Co., Inc. Optical lens for projecting light from an LED light emitter
USD633648S1 (en) 2008-01-31 2011-03-01 Star Headlight & Lantern Co., Inc. Face for optical element of a warning light module through which light generated in the module projects
US20110157889A1 (en) * 2009-12-31 2011-06-30 Au Optronics Corporation Diffusion Plate with at Least One Star Diffusion Structure and a Lighting Module Using the Same
USD712086S1 (en) 2013-03-05 2014-08-26 Star Headlight & Lantern Co., Inc. Optical lens for projecting light from LED light emitters
USD745713S1 (en) * 2014-05-01 2015-12-15 Peterson Manufacturing Company Combined stop, tail, turn lamp
USD747018S1 (en) * 2014-05-01 2016-01-05 Peterson Manufacturing Company Combined stop, tail, turn lamp
USD774686S1 (en) 2015-02-27 2016-12-20 Star Headlight & Lantern Co., Inc. Optical lens for projecting light from LED light emitters
USD775407S1 (en) 2015-02-27 2016-12-27 Star Headlight & Lantern Co., Inc. Optical lens for projecting light from LED light emitters
US20220120409A1 (en) * 2019-11-08 2022-04-21 Opple Lighting Co., Ltd. Lens and light source module

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2247672B1 (enExample) * 1973-10-12 1976-06-18 Alexandre Et Co

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1241886A (en) * 1916-07-12 1917-10-02 Levi Leroy Rowe Lens.
US1944154A (en) * 1930-02-10 1934-01-23 Gen Motors Res Corp Stop light lens
US2859334A (en) * 1954-09-09 1958-11-04 Edwin F Guth Company Louvers
US2937265A (en) * 1958-02-10 1960-05-17 Blitzer Bud Cellular lighting element and means for supporting the same
US3019334A (en) * 1956-12-26 1962-01-30 Willis L Lipscomb Cellular light control panel
US3368070A (en) * 1965-06-15 1968-02-06 United Lighting & Ceiling Co Modular closed louver panel system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1241886A (en) * 1916-07-12 1917-10-02 Levi Leroy Rowe Lens.
US1944154A (en) * 1930-02-10 1934-01-23 Gen Motors Res Corp Stop light lens
US2859334A (en) * 1954-09-09 1958-11-04 Edwin F Guth Company Louvers
US3019334A (en) * 1956-12-26 1962-01-30 Willis L Lipscomb Cellular light control panel
US2937265A (en) * 1958-02-10 1960-05-17 Blitzer Bud Cellular lighting element and means for supporting the same
US3368070A (en) * 1965-06-15 1968-02-06 United Lighting & Ceiling Co Modular closed louver panel system

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3996458A (en) * 1974-02-25 1976-12-07 Jones Terry D Ceiling system
US4462068A (en) * 1982-06-24 1984-07-24 Manville Service Corporation Luminaire with improved lens structure
US4761641A (en) * 1983-01-21 1988-08-02 Vidcom Rentservice B.V. Information display system
US20060187654A1 (en) * 2003-07-24 2006-08-24 Johannes Jungel-Schmid Ambient lighting system
US7217002B2 (en) * 2003-07-24 2007-05-15 Johannes Jungel-Schmid Ambient lighting system
US7452093B2 (en) * 2004-08-26 2008-11-18 Fujifilm Corporation Prism sheet and display device using the same
US20060050200A1 (en) * 2004-08-26 2006-03-09 Fuji Photo Film Co., Ltd. Prism sheet and display device using the same
US7742137B2 (en) * 2005-08-12 2010-06-22 Hitachi, Ltd. Display device and electrical appliance using the same
US20070046874A1 (en) * 2005-08-12 2007-03-01 Masaya Adachi Display device and electrical appliance using the same
US20090016067A1 (en) * 2007-07-12 2009-01-15 Hon Hai Precision Industry Co., Ltd. Optical plate and backlight module using the same
USD633648S1 (en) 2008-01-31 2011-03-01 Star Headlight & Lantern Co., Inc. Face for optical element of a warning light module through which light generated in the module projects
US20100080007A1 (en) * 2008-09-29 2010-04-01 Ping-Han Chuang Light distribution board having improved grating structure including a plurality of light gratings each with multiple focuses
US8197103B2 (en) * 2009-12-31 2012-06-12 Au Optronics Corporation Diffusion plate with at least one star diffusion structure and a lighting module using the same
US20110157889A1 (en) * 2009-12-31 2011-06-30 Au Optronics Corporation Diffusion Plate with at Least One Star Diffusion Structure and a Lighting Module Using the Same
USD632421S1 (en) * 2010-06-02 2011-02-08 Star Headlight & Lantern Co., Inc. Optical lens for projecting light from an LED light emitter
USD712086S1 (en) 2013-03-05 2014-08-26 Star Headlight & Lantern Co., Inc. Optical lens for projecting light from LED light emitters
USD745713S1 (en) * 2014-05-01 2015-12-15 Peterson Manufacturing Company Combined stop, tail, turn lamp
USD747018S1 (en) * 2014-05-01 2016-01-05 Peterson Manufacturing Company Combined stop, tail, turn lamp
USD774686S1 (en) 2015-02-27 2016-12-20 Star Headlight & Lantern Co., Inc. Optical lens for projecting light from LED light emitters
USD775407S1 (en) 2015-02-27 2016-12-27 Star Headlight & Lantern Co., Inc. Optical lens for projecting light from LED light emitters
US20220120409A1 (en) * 2019-11-08 2022-04-21 Opple Lighting Co., Ltd. Lens and light source module
US12320517B2 (en) * 2019-11-08 2025-06-03 Opple Lighting Co., Ltd. Lens and light source module

Also Published As

Publication number Publication date
FR2079195B1 (enExample) 1973-10-19
DE7103780U (de) 1973-01-18
CA920563A (en) 1973-02-06
GB1302648A (enExample) 1973-01-10
DE2104788A1 (de) 1971-08-19
FR2079195A1 (enExample) 1971-11-12

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