AU769164B2

AU769164B2 - Lighting devices for controlled distribution and for panel radiation

Info

Publication number: AU769164B2
Application number: AU42819/97A
Authority: AU
Inventors: Nobuo Oyama
Original assignee: S T I Japan KK
Current assignee: K K S-T-I-JAPAN
Priority date: 1997-10-23
Filing date: 1997-10-23
Publication date: 2004-01-15
Anticipated expiration: 2017-10-23
Also published as: AU4281997A

Description

-1- P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: LIGHTING DEVICES FOR CONTROLLED DISTRIBUTION AND FOR PANEL RADIATION The following statement is a full description of this invention, including the best method of performing it known to us: GH REF: P25329-A:MHK:RK LIGHTING DEVICES FOR CONTROLLED DISTRIBUTION AND FOR PANEL RADIATION FIELD OF THE INVENTION The present invention relates in general to lighting devices for controlled distribution of light or for uniform radiation through the panels of such lighting devices BACKGROUND OF THE INVENTION The conventional methods of controlling distribution of light of a lamp are to redirect or control flux of a light source with a reflector or a lens, or to cut a part of flux with an absorption body in order to eliminate the light which goes to outside of the desired area. However, the elimination of a part of the flux of a lamp for such an improvement has resulted in a low energy efficiency- Many of the conventional lighting devices for uniform :radiation through the panels of such lighting devices have a plurality of fluorescent lamps behind each of the translucent diffusion panels and radiate the flux of lamps out through each of the diffusion panels.

Such devices have failed to have sufficiently uniform light 0.90 intensity throughout the radiation panel due to cause of light and dark bands on the surface of the radiation panel along the arrangement of the fluorescent lamps. Elimination of such light and dark bands by arranging the lamps closer to one another or by using a high diffusion panel of conventional translucent material f or the radiation panel decreases the energy efficiency.

-'1M7 It is preferably an advantage of the present invention to provide a lighting device in a distribution control type which forwards much greater amount of the flux of a lamp (lamps) into a specified range of light distribution and much less amount of the flux to the outside of the range than any conventional device does, i.e. a lighting device in a distribution control type which provides a desired light distribution with a high energy efficiency.

It is preferably a further advantage of the present invention to provide a lighting device in a radiation panel type with no cause of light and dark bands on the radiation panel, i.e. uniform radiation throughout the panel with a high energy efficiency in exploitation of the above light distribution control technology.

SUMMARY OF THE INVENTION According to a first aspect of the present invention, there is provided a lighting device for a controlled distribution of light, comprising: a light source; a flat reflector positioned in front of said light source and angled to redirect flux from said light source; an ellipsoidal reflector positioned behind the light source and positioned to reflect light toward said flat .o "reflector; and a diffuser which diffuses such redirected flux into 30 specific directions, wherein the diffuser is a transparent S..2 -2 or reflective body embodying a plurality of ridges or ridges and grooves arranged, wherein each ridges in the arrangement or ridges, or at least each of either ridges or grooves in the arrangement or ridges and grooves has a cross-sectional shape that in partially circular, elliptic, sine curved or curved in other way, whereby redirected flux incident to either face of the diffuser is diffused in a specific direction.

Preferably, the said transparent or reflective body has a planar or panel-like shape and a plurality of ridges or ridge and grooves is formed substantially parallel to one another at least on one of the faces of such transparent body or on the reflective surface of such reflective body.

Preferably, the said transparent or reflective body comprises a plurality of mono-filaments or cylinders arranged next to one another or bundled together.

Preferably, the said means to redirect the flux is a reflector or a set of reflectors which collects and condenses the flux of the said light source into a specified beam angle.

Preferably, the device further comprising a second reflector to further redirect all or a part of the beam which is with the above reflector or set of reflectors, to 3 the said diffuser.

Preferably, a set of optical fibers or a light guide pipe transmit(s) the flux condensed in claim 4 or further redirected in claim 5, to the said diffuser.

Preferably, the device further comprises a spherical reflector positioned between said light source and said flat reflector, and having an aperture which is aligned with said light source and said flat reflector, said spherical reflector of being positioned to interrupt a portion of said flux to control the range of the distribution of diffused rays which is made with the said diffuser.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred forms of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic view of the structure of a lighting device controlled distribution type in regard to *the present invention; Figure 2 is a schematic presentations of a light distribution obtained with the lighting device described in Figure 1; Figure 3 is cross-sectional schematic views of the diffuser in Figure 1 in variation, wherein or a single solid line represents a circle, a circular arc or a curve, and a double solid line represents -3aa straight line Figure 4 is a schematic view of the structure of a lighting device in a controlled distributuion type in regard to the present invention using a set of reflectors to further control diffused rays; Figure 5 is schematic presentations of a igth distributuion obtained with the lighting device described in Figure 4. wherein represents the light distributulon in the cross -section at Line A. and represents the same at Line B Figure 6 is a perspective view of flux obtained with the lighting device described in Figure 4; Figure 7 is a perspective view of a lighting device in a radiation Panel type in regard to the present invention, wherein the distance between the face of the radiation panel and the face of the reflection panel gradually decreases in traveling from the light entering end to the opposit end; Figure 8 is a presentation of the distributuion of light intensities obtained on the radiation panel of the lighting device described in Figure 7. wherein a conventional acrylic translucent diffusion a:...:panel is used as the radiation panel; Figure 9 is a presentation of the distribution of light intensities obtained on the radiation panel of the lighting device described in Figure 7, wherein a diffuser described in Figure 3 is used as the radiation panel Figure 10 is a perspective view of the structure of a lighting device in a radiation panel type, wherein the distance between the face of the radiation panel and the face of the reflection panel gradually decreases towards the middle line of the radiation panel.

-4and light enters from both the opposit ends of the optical component Figure 11 is a perspective partial view of the lighting device described in Figure 10, wherein fluorescent lamps are used as the light sources.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows that the flux of a 35 watt short-arc metal-halide lamp 1 is collected and redirected into a condensed beam with an ellipsoidal reflector 2 and a spherical reflector 3. and partially further redirected the beam with a flat reflector 4 to a transparent *:diffusion body 5 which has a 'diffusion axis All the said reflectors are made by making specific optical coating on their glass bodies so that they reflect visible rays. transmit infrared rays and consequently eliminate most of infrared rays from the beam insident to the diffuser 5. The ellipsoidal reflector 2 alone or together with the spherical reflector 3 constitutes the first means to redirect the flux, and the flat reflector 4 constitutes the second means for the. redirection in regard to the present invention.

Projection of the diffused rays from the diffuser 5 to a wall provides a light distribution as shown in Figure 2.

The diffuser 5 is a transparent acrylie plate which emobodies a plurality of ridges nexting to one another on a face of the said plate, wherein each of the ridges has cross sectional shape of a circular arc. The diffuser 5 may also be a transparent plate emboding an arrangement of a plurality of either ridges or ridges and grooves each of which has a cross -sectional shape that is partially circular, elliptic, sine curved or curved in any other way as shown in Figure 3. The diffuser 5 may also be either a transparent or a reflective body of plurality of mono -filaments or cylinders bundled together.

Optical fibers or a light guide pipe may receive the flux condensed by the ellipsoidal reflector 2 alone or with the spherical reflector 3, directly from the ellipsoidal reflector 2 or through the flat reflector 4, in order to transmit the flux to the diffuser at a distant place. Projection of the diffused rays to a wall with the flux thus redirected and transfered, provides a light distrifution similar to one shown in Figure 2.

As shown in Figure 4, a set of flat riflector 6 is so placed in front of the diffuser 5 that such set of reflectors controls the direction of the diffused rays. Projection of the flux of such controlled diffused rays to a wall at distance A and B are shown Figure 5 and The shapes of the light distribution at distance A and B represent the cross- sectional shapes of the flux at distance A and B. This implies that the diffusion from the diffuser 5 is controlled into a shape of a frustum of pyramid which expands forwards.

Figure 7 shows a thin box having thickness of 15 cm, hight of cm and width of 100 cin is used as the radiation panel T, and a 3 mm thick acrylic reflection panel 8 is placed behind the radiation panel 7, keeping the reflective surface faced to the radiation panel 7. The distance between the said panels is set to be 13.7 cm at one of the shorter ends 9 of the box and gradually decreased towards the opposit end 10, in a straight line. Reflection -6panels 11 and 12 are placed at both the longer ends. keeping the reflective faces inside.

Flux of light which has a shape of a frustrum, of pyramid as shown in Figure 6, enteres between the radiation panel 7 and reflection panel 8 at the end 9 of thus structured optical component 13. The distribution of the light intensities an the surface of the radiation panel 7 is shown in Figure 8. Each number on the radiation panel shows the intensity in lux at each point where such number is shown. The result implies the following: Average intensity 1873 lux Unifoirmty (Max. intensity 2200 -1.3 \Min. intensity)J 1700 Effd~f~ (Total flux radiated 1873 x Effiienc -Total flux radiae 270003 In the above optical component 13, the translucent radiation panel 7 is replaced with a transparent diffusion Panel which has the structure the same to the diffuser 5. The diffusion panel is so placed that its ridges face outside and is orthogonal to the longitudinal axis of the optical compornent 13. Light intensities on the radiation panel 7 made of such diffusion panel is shown in Figure 9. The result implies the following: :Average intensity 2173 lux Unifrmiy (Max. intensity 2500 1.2 %,Min. intensity 2000 -2 Efficiency Tota flux radiated ):1086 x 0.5 0.4 (Ttlflux radiated 2700 Figure 10 shows the Optical component 13, wherein the distance between the radiation panel 7 and the reflection panel 8 gradvelly decreases in traveling from both the said opposit ends 9 and -7to the middle line of such two ends. Flux of a fluorescent lamp enters between the said panels at each of the said opposite ends 9 and In any of the above lighting devices in a radiation panel type, an increase of the distance between the said panels 7 and 8 towards the opposite end or the middle line for a short distance from each light entering end improves the uniformity of the radiation over the surface of the radiation panel 7.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

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Claims

2. The device as claimed in claim i, wherein the •said transparent or reflective body has a planar or panel- 25 like shape and a plurality of ridges or ridge and grooves is formed substantially parallel to one another at least one of the faces of such transparent body or on the reflective surface of such reflective body.
3. The device as claimed in claim i, wherein the 0• •said transparent or reflective body comprises a plurality of mono-filaments or cylinders arranged next to one another or bundled together. 9 0oo
4. The device as claimed in claim i, wherein the said means to redirect the flux is a reflector or a set of reflectors which collects and condenses the flux of the said light source into a specified beam angle. The device as claimed in claim 4, further comprising a second reflector to further redirect all or a part of the beam which is with the above reflector or set of reflectors, to the said diffuser.
6. The device as claimed in claim 4, wherein a set of optical fibers or a light guide pipe transmit(s) the flux condensed in claim 4 or further redirected in claim 5, to the said diffuser.
7. The device as claimed in claim i, further comprising a spherical reflector positioned between said light source and said flat reflector, and having an aperture which is aligned with said light source and said flat reflector, said spherical reflector being positioned "•to interrupt a portion of said flux to control the range S"of the distribution of diffused rays which is made with the said diffuser.
8. The device substantially as herein described with reference to the accompanying figures. Dated this 7th day of November 2003 30 KK S-T-I-JAPAN By their Patent Attorneys GRIFFITH HACK eeee 10