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Publication numberUS1757527 A
Publication typeGrant
Publication dateMay 6, 1930
Filing dateNov 13, 1926
Priority dateDec 4, 1925
Publication numberUS 1757527 A, US 1757527A, US-A-1757527, US1757527 A, US1757527A
InventorsPoul Henningsen
Original AssigneeMessrs Louis Poulsen & Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Reflector for incandescent lamps
US 1757527 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

y 6,1930. I P. HENNINGSEN 1,757,527


The present invention refers to a reflector arrangementvfor emitting diffused light and in particular to a special arrangement in such reflectors which consist of a system of' lamp shades which completely surround the source of light 'so'that no radiating-rays can meet the eye directly.

The characteristic feature of the invention consists inthe fact' that shade surfaces are turned towards the source of light at an angle the indirect and semi-direct light) will be 60 of less than 45 degrees with the rays of light. But the shape of the shades only forms in figurative manner. a part of the present in-, vention and in their distribution regard has only been taken to produce a suitable air cool- With the customary dullness of the spherical glass bulb of incandescent lamps or by surrounding the lamp with a clouded globe the filament will be completely surrounded by a white surface so that, if the eye be assumed to be in the place of the filament, it would only see a White or other diffuse surface in all directions a By the present invention the same object is attained, as the eye, assumed to be in the place of the filament, will only be able to see difl'use surfaces, but the feature which is decisive for the lighteconomy and which forms the basis for the present invention consists in the fact that all these surfaces, contrary to the inner surface of the clouded spherical surface around the filament, will form an angle of less than with'the rays of light. It is thereby obtained that the light which is necessarily reflected by the diffuse surfaces owards the filament (and heats the same, and

the gas of the lamp), become essentially less than if the angle of the surface with the rays of light proceeding from the filament is more than 45 degrees. I l

In order to increase the utilization of the light the diffused light which is reflected from a diffuse surface to the back of the diffuse s'ur face below it, must be utilized as greatly as possible and therefore the back of the shades are made bright or as mirrors,

The light arrangement which closest approaches that here described is the simple incovered with dust. Besides all surfaces are here placed at an acute angle to the rays of light. v

The invention has, in a single modification, been shown in the drawing, in which Fig. 1 is a vertical section through such a system of shades, a Fig. 2 is a sectional view showing the reilection from a small part of a diffuse reflecor. i

It should be here said that the drawing should only be considered as a diagram for explaining the invention, and all parts which are not necessary for understanding the in- VBIltlOIl-llfiVB therefore been omitted- In the drawing the numeral 1 indicates the filament of the lamp 2 and above the same is disposed a shade 3 the curvature of which is such that the light will never strike the shade at an angle of less than 45 degrees with the perpendicular. Beneath this shade but with its upper edge on a level with the lower edge of the shade 3 is disposed another shade 4 with the same curvature and position relatively to the rays of light.

Lastly a third shade 5 is disposed beneath this shade 4 with the same curvature and so arranged that no dire'ctrays of light can pass between the shades 3, 4 and 5. Lastly an undershade 6 is provided which may be bright on its inner side and which reflects the light onto the dulled shades. This form a part of the invention.

In the drawing it is shown that the rays of light 9, 7 and 11 emitted by the filament onto the shades 3, 4 and 5 will be spread as shown byarrows so that the strongest light effect will be in the directions 8, 10 and 12.

"In Fig. 2 this circumstance is more closely shade does not i explained. 13 is the surface of one of the dullshades 3,4 or 5. l The light from ,the filament is indicated the line and strikes 7 against the shade within the'shaded angle 24 the bordering lines of which are 13 and 14. The ray mentioned 15 when reflected by the surface 13 will assume the form of a bundle of rays, hereindicated by the numerals 17 18, 19, 20, 21, 22, 23. The size of these rays will differand the ray 17 will always be greatest, but the difierence in their size will dependon the dullness of the shade;

It is thus possible to regulate the light emission from a lamp by varying the degreeof dullness of the shades or of parts or individual portions of them whereby the rays 8,. 10 and 12' in Fig. 1 will be increased relatively to the other emission.

It is hereby rendered possible, in an easy manner, to let the light from the shade become essentially luminous towards outside, that is to say to spread the light more in a room with great dullness of the shades, whereby the rays '8, 10 and 12 willbe weakened, or to gather the light greatly towards the centre with slightly dull shades, chiefly the outer part of shade 3, the whole shade 4 and the upper part of the shade 5Q It is-evident that the incident ray 15 forms an angle with the perpendicular which is greater than degrees (the angle between 14 and 16).-

The intensity of ray 1? will be determined bothby the dullness of shade 13 and by the angle between 15 and 16 being as large as pos-' sible. It is therefore essential that the ray I 15 falls within the shaded area 24 between the lines 13 and 14, as it then willJalways form I e perpendicular which is an angle with th greater than 45.

Having now described my invention, what I claiin as new and desire to secure by Letters 4 light, the inner surfaces ofsaid shades being Patent is A reflector for diflusing the light of incandescent lamps comprising a plurality of concentric downwardly concave shades disposed above and below the plane of the source of directed toward the source of light, the surfacesof said shades making at all points angles of lessithan 45 with a line to the source.

of light, the inner surfaces of the' shades being dulled. i

' In testimony whereof I-aflix in signature. POUL HENN NGSEN,

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3215980 *Jan 14, 1963Nov 2, 1965Eclairage TechReflecting device for public street lighting appliances and lighting appliances fitted with this device
US3702930 *Mar 12, 1971Nov 14, 1972Olivetti & Co SpaRemote illuminating apparatus
US4034217 *Jun 20, 1975Jul 5, 1977Roger Louis DumontOptical device for lighting apparatus, with a plurality of combined reflectors
US4218727 *Jul 3, 1978Aug 19, 1980Sylvan R. Shemitz And Associates, Inc.Luminaire
US4310876 *Mar 17, 1980Jan 12, 1982Small Jr Edward ALighting fixture and method using multiple reflections
U.S. Classification362/346
International ClassificationF21V7/04, F21V7/00
Cooperative ClassificationF21V7/04
European ClassificationF21V7/04