WO2011133118A1

WO2011133118A1 - Method for the elimination of multiple shadows in light fixtures having point light sources, particularly in led fixtures

Info

Publication number: WO2011133118A1
Application number: PCT/SK2011/050003
Authority: WO
Inventors: Pavel PETRÍK
Original assignee: S POWER EXPORT - IMPORT SRO
Current assignee: S POWER EXPORT - IMPORT SRO
Priority date: 2010-04-20
Filing date: 2011-04-19
Publication date: 2011-10-27
Anticipated expiration: 2012-10-20
Also published as: SK50092010A3; CZ2012674A3

Abstract

The method for the elimination of the formation of multiple shadows in light fixtures having point light sources, particularly LED fixtures, is based on that using a light- transmitting cover (2) having a grid pattern of protrusions (4) or straight band-like or curved structures deployed in close proximity or in touch or in mutual overlap (3) of the radiated light spot of the adjacent light point sources (1), particularly LEDs, on the light-transmitting cover (2), a close fitting or even continuous or even overlapping light spot (5) is formed on the light-transmitting cover (2). The design of a light fixture having point light sources, particularly a LED fixture, with the elimination of the formation of multiple shadows is such that the light- transmitting cover (2) having a grid pattern of protrusions or straight band-like or curved structures with a grid (M) of up to 500 mm is placed in a distance (L) of up to 2000 mm as a close proximity or touch or mutual overlap (3) of the radiated light spot of the adjacent light point sources (1), particularly LEDs, on the light- transmitting cover (2), arranged with the spacing (K) of up to 450 mm.

Description

Method for the elimination of the formation of multiple shadows in light fixtures having point light sources, particularly in LED fixtures Technical Field

[0001] The invention generally concerns a method for the elimination of the

formation of multiple shadows in light fixtures having point light sources, particularly in LED fixtures, and the design of light fixtures having point light sources, particularly light fixtures with LEDs, particularly in linear arrangement and with a frontal light-transmitting cover, useful in public, industrial, and private sectors. The invention in general falls within the field of light technology.

Background Art

[0002] In general, various premises in diverse fields of use were commonly lit by discharge tube light fixtures, mostly with neon tubes. Discharge tube light fixtures were designed as elongated flat objects of essentially a flat box design with frontal transparent or matted cover of the light-emitting surface. Currently, light fixtures with discharge tubes are being replaced with light fixtures with power LEDs arranged linearly in series. The light fixture still has the shape of essentially a flat box or trough design. On the bottom of the flat box- or trough structure, there are spaced power LEDs covered with frontal transparent or matte cover of the light-emitting surface. The frontal transparent covers currently used include those with a smooth surface, or the surface of the frontal transparent cover represents a regular system of protrusions with sharp edges, for example, having the shape of pyramids. Or they comprise elongated objects with a pyramid cross-sectional profile. The distance between the LEDs and the front transparent cover was dictated only by aesthetic or design considerations of the flat box or trough body of the light fixture and the density of the LED placement was dictated only by the required intensity of light.

[0003] In prior art light fixtures, these three parameters were not optimised in any way; they were not optimised even with respect to the radiation angle of the LEDs which led to persistent problems of formation of multiple shadows as a result of the fact that alternately repeating light maps with higher and lower light intensities were forming on the surface of the transparent cover.

[0004] The disadvantage of the above-described light fixture with power LEDs deployed mostly linearly into a single band is the formation of multiple shadows produced by power LEDs spaced in a certain arrangement. If such a fixture sheds light on a working area in manufacturing enterprises, an object moving under the light fixture forms multiple shadows or even a stroboscopic effect on the working area which has a disturbing effect on the person and which may result in subconscious reflexes of ducking the head, body, or hand from the perception of the shadow believing that it is a real object that should not be there at that particular moment. This may result in work injuries or damage to property may be caused by

unintentional subconscious reflexes.

[0005] The above-mentioned deficiencies stimulated the effort to design a

different system of lighting particularly of work premises so that the formation of multiple shadows is eliminated.

[0006] This effort resulted in a newly created method for the elimination of the formation of multiple shadows in light fixtures having point light sources, particularly in LED fixtures, and a light fixture with an arrangement of, in particular, power LEDs in at least one band or an n-matrix eliminating the formation of multiple shadows implemented by technical means described below in this application.

Disclosure of Invention

[0007] It was determined experimentally that with light fixtures having point light sources, particularly LED fixtures, the efficiency of eliminating the multiple shadows is influenced by the distance between the point light sources, particularly LEDs, the distance of the point light sources, particularly LEDs, from the light-transmitting cover, the grid, the shape of protrusions on the light-transmitting cover, and lastly the radiation angle of the light fixtures having point light sources, particularly LEDs. This led to the invention of a method for the elimination of the formation of multiple shadows in light fixtures having point light sources, particularly LED fixtures, based on the fact that using a light-transmitting cover having the grid pattern M of protrusions or straight band-like or curved structures deployed in close proximity or in touch or in mutual overlap of the radiated light spot of the adjacent light point sources, particularly LEDs, on the light-transmitting cover, a close fitting or even continuous or even overlapping light spot js formed on the light-transmitting cover. The continuity of the light spot is parametrically dependent on the spacing K of the adjacent point light sources, particularly LEDs, and is also dependent on the distance L of the point light sources, particularly LEDs, from the light-transmitting cover. And subsequently, the radiated light spot of the point light sources, particularly LEDs, formed on the light-transmitting cover, is dependent on the grid M of the pattern of protrusions or straight band-like or curved structures of the light-transmitting cover and on the radiation angle of the point light sources, particularly LEDs.

This method led to the design of a light fixture having point light sources, particularly a LED fixture, with the elimination of the formation of multiple shadows according to this invention, which substantially eliminates the above-mentioned deficiencies of the prior art and which is based on the fact that the light-transmitting cover having a grid pattern of protrusions or straight band-like or curved structures with a regular or irregular and/or linear or non-linear grid M from minimum values up to 500 mm is placed in a distance L from minimum values up to 2000 mm as a close proximity or touch or mutual overlap of the radiated light spot of the adjacent light point sources, particularly LEDs, on the light-transmitting cover, arranged with the spacing K from minimum values up to 450 mm. The radiated light spot of individual point light sources, particularly LEDs, is smaller than the - radiation angle of individual point light sources, particularly LEDs, as a result of the fact that light diffraction on the edges of the radiation angle on the grid M of the patterns of protrusions or straight band-like or curved patterns does not contribute with its large angle to the formation of the radiated light spot of individual point light sources, particularly LEDs. The spacing K of point light sources, particulary LEDs, is given by their required installed power and by the required intensity of lighting of the lit space. The point light sources, particularly LEDs, can be arranged linearly or non-linearly on a planar or curved surface. Also, the point light sources, particularly LEDs, with their radiation angle can be arranged with a regular or irregular spacing K. Point light sources, particularly LEDs, thus arranged are arranged from the base up to the apexes of the protrusions of the light- transmitting cover in a distance L from minimum values up to 2000 mm. This will create a close fit or touch or overlap of the radiated light spot of the adjacent point light sources, particularly LEDs, on the light-transmitting cover. The light-transmitting cover can be clear to matte or translucent. The light-transmitting cover can have planar or curved surface of various shapes. The light-transmitting cover contains regularly or irregularly repeating pattern of protrusions with the grid M from minimum values up to 500 mm. The protrusions of the regularly repeating pattern can have the shape of a half-lens or part of a cone or a bellow or a pyramid of straight band-like or curved patterns with a rounded or sharp transversal cross- section of full or bevelled geometric shapes. The light fixtures with point light sources can comprise, for example, halogen bulbs.

[0009] The advantages of the design of light fixtures having point light sources, particularly LED light fixtures, eliminating the formation of multiple shadows according to this invention consist in the fact that, compared to light fixtures having point light sources particularly with a linear

arrangement of LEDs of the prior art, the formation of multiple shadows is substantially or completely eliminated.

Brief Description of Drawings

[0010] A light fixture having point light sources, particularly a LED light fixture, eliminating the formation of multiple shadows according to this invention - will be described with reference to the Figure showing the design of a LED light fixture using the parameters K, L, M, and the radiation angle.

Mode(s) for Carrying Out the Invention

[0011] It is understood that the light fixture having point light sources eliminating the formation of multiple shadows according to this invention is made using methods and materials known to persons skilled in the art.

[0012] Persons skilled in the art will find or be able to find, using no more than routine experimentation, many equivalents to the specific embodiments of the invention. Such equivalents will be included in the scope of the claims below.

[0013] Example 1

[0014] This example of a.specific embodiment describes the design of a LED light fixture having a linear arrangement of LEDs 1_ eliminating the formation of multiple shadows according to this invention shown in the Figure

illustrating its three parameters K, L, M. The light fixture consists of a metallic body having the shape of a trough with carriers of power LEDs 1_ affixed to its bottom part. The trough of the light fixture body is enclosed with a flat light-transmitting cover 2. The light fixture, of course, includes electrical wiring. The power LEDs 1_ are mutually linearly arranged with the spacing K of 35 mm which is given by the power of the LEDs _1 and by the required intensity of lighting in the lit space. The flat light-transmitting cover 2 is a transparent plastic board with a regularly repeating pattern of elongated straight structures 4 with the grid M of triangular transversal cross-section. The grid M in this case is 0.5 mm. The parameter L as the distance of the LEDs _1 from the flat light-transmitting cover 2 in this case is 18 mm and is given by the touch 3 of the radiated light spot of the adjacent LEDs 1_ on the light-transmitting cover 2.

[0015] Example 2

[0016] This example of a specific embodiment describes the second design of a light fixture having a linear arrangement of LEDs 1_ eliminating the formation of multiple shadows according to this invention. The light fixture has been to a large extent described in the previous Example. The difference consists in the fact that it comprises a light fixture shaped as a flat box with power LEDs 1_ affixed in three parallel arrangements on their carriers. The flat box of the light fixture body is enclosed with a

semitransparent flat light-transmitting cover 2. The light fixture, of course, includes electrical wiring. Moreover, there is a different design of the flat cover 2 using a semitransparent plastic board with a regularly repeating pattern of slightly rounded bevelled pyramidal protrusions. Optionally, the pyramidal protrusions 4 can be sharp.

[0017] Example 3 [0018] This example of a specific embodiment describes the third design of a light fixture having a linear arrangement of LEDs 1_ eliminating the formation of multiple shadows according to this invention. The light fixture consists of a body having the shape of a bar with power LEDs 1_ affixed thereto with their carriers. The bar of the light fixture body is closely fitted with a semitransparent flat cover 2 forming thus a monolithic unit. The light fixture, of course, includes electrical wiring. The semitransparent flat cover 2 is a transparent plastic layer with a regularly repeating pattern of flattened conical protrusions with the grid M.

[0019] Example 4

[0020] This example of a specific embodiment describes the fourth design of a light fixture having a linear arrangement of point light sources 1_ eliminating the formation of multiple shadows according to this invention. The light fixture consists of a body having the shape of a bar with halogen light source sockets _1 affixed thereto. The bar of the light fixture body is fitted with a semitransparent flat cover 2. The light fixture, of course, includes electrical wiring. The flat transparent cover 2 is a transparent plastic layer with a regularly repeating pattern of elongated straight structures 4 with the grid M of triangular transversal cross-section. The transparent flat light- transmitting cover 2 is placed in a distance from the point halogen light sources 1_ which distance corresponds to the close proximity 3 of the radiated light spot of the adjacent point halogen light sources 1_ on the transparent flat light-transmitting cover 2. At this distance of close proximity already, the effect of eliminating the formation of multiple shadows starts to appear and is sufficiently effective.

Industrial Applicability

[0021] The method for the elimination of the formation of multiple shadows in light fixtures having point light sources, particularly in LED fixtures, and the light fixture eliminating multiple shadows according to this invention represent a technology useful in all areas where the lighting of particularly working areas is required.

Claims

1. Method for the elimination of the formation of multiple shadows in light fixtures having point light sources, particularly LED fixtures, characterised in that using a light-transmitting cover (2) having a grid pattern of protrusions (4) or straight band-like or curved structures deployed in close proximity or in touch or in mutual overlap (3) of the radiated light spot of the adjacent light point sources (1), particularly LEDs, on the light-transmitting cover (2), a close fitting or even continuous or even overlapping light spot (5) is formed on the light-transmitting cover (2).

2. Method for the elimination of the formation of multiple shadows in light fixtures having point light sources, particularly in LED fixtures, according to claim 1 characterised in that the continuity of the light spot (5) is dependent on the spacing (K) of the adjacent point light sources (1), particularly LEDs, and on the distance (L) of the point light sources (1), particularly LEDs, from the light- transmitting cover (2).

3. Method for the elimination of the formation of multiple shadows in light fixtures having point light sources, particularly in LED fixtures, according to claim 1 characterised in that the radiated light spot of the point light source (1), particularly a LED, formed on the light-transmitting cover (2), depends on the grid (M) of the pattern of protrusions or straight band-like or curved structures of the light-transmitting cover (2) and on the radiation angle of the point light source (1), particularly a LED.

4. A light fixture having point light sources, particularly a LED fixture, with the elimination of the formation of multiple shadows comprising a lighting fixture body and a light-transmitting cover characterised in that the light-transmitting cover (2) having a grid pattern of protrusions or straight band-like or curved structures with a regular or irregular and/or linear or non-linear grid (M) of up to 500 mm is placed in a distance (L) of up to 2000 mm as a close proximity or touch or mutual overlap (3) of the radiated light spot of the adjacent light point sources (1), particularly LEDs, on the light-transmitting cover (2), deployed with the spacing (K) of up to 450 mm.

5. A light fixture having point light sources, particularly a LED light fixture,

eliminating the formation of multiple shadows according to claim 4 characterised in that the point light sources (1), particularly LEDs, are arranged linearly or nonlinearly on a planar or curved surface in several parallel arrangements.

6. A light fixture having point light sources, particularly a LED light fixture,

eliminating the formation of multiple shadows according to claim 4

characterised in that the light-transmitting cover (2) is clear to matte.

7. A light fixture having point light sources, particularly a LED light fixture,

eliminating the formation of multiple shadows according to claim 4

characterised in that the light-transmitting cover (2) has a planar or curved surface.