WO2006033090A1

WO2006033090A1 - Multi-aperture light pipe

Info

Publication number: WO2006033090A1
Application number: PCT/IE2005/000101
Authority: WO
Inventors: Anthony Farrell; David Kennedy
Original assignee: Dublin Institute Of Technology
Priority date: 2004-09-21
Filing date: 2005-09-21
Publication date: 2006-03-30
Also published as: GB0420944D0; GB2418222A

Abstract

The invention relates to a light pipe for transmitting light internally into a building or structure comprising an elongate light pipe body (18) having a first end (5) arranged to capture light and a second end (6) spaced therefrom and at least one side wall (7) defining a conduit (9); an aperture (4) in the side wall between the first and second ends; and at least one optical element positioned within the conduit and arranged so as to reproduce an image of a feature external to the building for view through the aperture. The invention allows for multi apertures in the light pipe allowing for greater efficiency and use of natural light than conventional light pipes which generally have only one opening at one of its ends. Additionally, the optical element arrangement allows a real image of the sky to be reproduced inside the building.

Description

Title

Multi-Aperture Light Pipe

Field of the Invention

The present invention relates to the field of illuminating buildings with natural light. This invention in particular relates to the use of light pipes for directing light into buildings in a more efficient and natural way.

Background to the Invention

A light pipe is generally a tubular structure with a reflective inner surface and having a natural light collector at its upper end and a diffuser at its lower end. The natural light collector is arranged to be positioned on the roof of a building and the diffuser is arranged to be located in the area it is desired to illuminate with the light pipe. Natural light collectors typically have an optically transparent dome which may be integrated and sealed into the roof of a building. The dome would usually, house a mirror that is arranged to optimally collect sunlight. Light pipes of this-design are commercially available and are known in the art.

European Patent Application Number EP 1 306 606 A1 to Energo Project s.r.l describes a tubular skylight for lighting rooms with natural light comprising a tubular body with a reflective inner surface that leads into a room and has as its external end, a natural light collector assembly and at its terminal end a light diffuser. The collector assembly includes a "mirror-finished body" in the shape of a cylindrical band with internal and external mirror-finished surfaces. The collector is said to collect natural light from all directions.

United States Patent Number 5, 099, 622 to Sutton describes a skylight comprising a tubular body closed at each ends with transparent surfaces thereon. A reflector unit is located in the surface protruding through the roof and is substantially shaped such that it bends about the vertical and horizontal axes and faces towards the direction of the sun's path. It is said that it is preferable that the internal surfaces of the skylight tube are coated with reflective material for the maximum transmission of light there-through.

United States Patent Number 5, 896, 713 to Chao et al., is directed towards a tubular skylight that can be installed in a building during construction of the building. The tubular skylight is supported in the building between the ceiling and the roof of the building by a support ring that is connected to the ceiling joists or the ceiling dry wall. The skylight includes a cover seal that establishes a seal between the roof dome of the skylight and the tube, and that also spaces the flashing of the skylight from the tube to prevent galvanic corrosion and to inhibit heat transfer between the flashing and the tube.

United States Patent Number 6, 035, 593 also to Chao et al., describes an assembly for effectively sealing the interior of a tubular skylight so that moisture and dust from inside the illuminated room and/or the external environment does not enter the skylight and thereby reduce the light transmissive properties of the skylight.

International Patent application Publication Number WO 02/081838 of Solatube International, Inc. discloses a skylight tube with reflective film and surface irregularities to optimise the light transmission into the building and to reduce un-diffused focal points that result in "hot spots" in the room sought to be lighted i.e. bright spots that appear on the walls, floor etc., of the room in which the tubular skylight is installed.

German Patent No. DE 3 130 715 discloses a light shaft for basement windows to admit daylight to bottom floor interiors with one or more mirroring surface fitted inside so that the occupants can see views of the outside. The English language abstract from the Patents Abstracts of Japan (Japanese Patent Office) for Japanese Patent No. JP 0 502 5945 discloses the use of an elevator shaft for introducing natural light to a plurality of floors in a building. The English language abstract from the Patents Abstracts of Japan (Japanese Patent Office) for Japanese Patent Application No. JP2003321931 discloses a light duct for installation in a building for taking in natural light and guiding it to a desired floor irrespective of the arrangement of columns and beams forming the building. The English language abstract from the Patents Abstracts of Japan (Japanese Patent Office) for Japanese Patent Application No. JP2001193294 disloses a well hole space having a skylight with an openable window arranged at the upper end of the well hole for ventilation and delivering natural light to a room. The Englishjanguage abstract from the World Patent Information, Derwent for SU 699 134 discloses a light shaft with manual or automatic louvers for allowing regulation of light flow into both stories of a building.

All of the above prior art is primarily concerned with the efficient capturing of light at one end of the light pipe and to emitting the capturing light into a building at the other end of the light pipe.

In general, there is a need for an improved light pipe system for buildings to direct light into the interior space of a building in a more efficient and natural way.

Object of the Invention

It is an object of the present invention to provide an improved light pipe for buildings to provide a natural light source to the interior space of a building and enhance the internal environment of the building and for directing light into buildings in a more efficient and natural way.

A further object of the invention is to provide a controllable adjustable- mechanism to control or adjust the level or amount of the light and an outside view being transmitted through an aperture in a light pipe.

Summary of the Invention

The present invention, as set out in the appended claims, provides a light pipe for transmitting light internally into a building or structure comprising: (i) an elongate light pipe body having a first (upper) end arranged for capturing light and a second (lower) end spaced therefrom and at least one side wall defining a conduit; (ii) an aperture in the side wall between the first and second ends; and,

(iii) at least one optical element positioned within the conduit and arranged so as to reproduce an image of a feature external to the building or structure for viewing through the aperture.

This aspect of the invention provides a very simple device, which provides a means for providing natural light into a building, in a manner which is verypleasing to an occupant of the building or structure being so illuminated. In general such an occupant would see only bright (reflected) sunlight coming from the lightpipe in a conventional light pipe set-up. Indeed with a conventional light pipe the occupier may not even be aware that the light is natural light. The present invention provides an effect where the aperture acts in a window type manner insofar as at least a portion of the view through the aperture is taken up with a view of an external feature.

Generally, a light pipe arrangement in accordance with the present invention comprises an elongate body designed to run from a position or space external to a building to a lower level within the building, preferably from the roof of a building all the way to the lowest occupied floor such as the ground floor or a basement.

One of the advantages of the present invention is that the at least one aperture located in (defined in) the side wall of the light pipe has an associated optical element which acts as an image re-direction device to direct light and the image of a feature external to the building through the aperture and into building. This assists in maintaining the required illuminance levels while also providing a very aesthetically pleasing view.

In another aspect of the present invention there is provided a light pipe for transmitting light internally into a building or structure comprising: (i) an elongate light pipe body having a first end arranged for capturing light and a second end spaced therefrom and at least one side wall defining a conduit; (ii) an aperture in the side wall between the first and second ends; and,

(iii) at least one reflective element positioned within the conduit and spaced apart from the side wall and arranged so as to reflect light from within the light pipe through the aperture.

Providing a reflective element in addition to the normal internal reflective coating of the light pipe is beneficial as it allows for a greater amount of light to be transmitted through the aperture into the building in question, it being appreciated that the light pipe will reflect an amount of light through the aperture without the presence of the reflective element. However this aspect of the invention is concerned with increasing and/or controlling the amount of light transmitted to the interior of the building/structure.

In one arrangement the reflective element may be substantially of the same dimensions as the aperture. In this way the surface area of the reflective element will match that of the aperture so that the amount of light being reflected from the reflective element is suitable for transmission through the aperture.

It is desirable, additionally or alternatively, that the shape of the reflective element is substantially similar to that of the light pipe, and in particular the aperture therein. In particular where the light pipe is substantially cylindrical in shape, and therefore the aperture is defined within that shape also, it is desirable that the reflective element is similarly shaped having a part, substantially cylindrical shape.

It will.be appreciated that both aspects of the invention can be combined in one embodiment as is illustrated in the embodiments illustrated in the accompanying drawings. In particular it is desirable to provide a light pipe that can provide an image of a feature external to a building or other structure for viewing from within the building or structure and additionally to include a reflective element as described above to provide more light through the aperture. It will be appreciated that the provision of an image of a feature generally external to a building or structure, within the building or structure will involve the provision of an amount of light. However the amount of light generally provided in relation to the image will not generally be sufficient to substantially illuminate a space within the building or structure. Accordingly the reflective element used within the present invention is generally arranged to provide sufficient light to substantially illuminate a space within the building or structure. Generally then the light provided by the reflective element will be direct sunlight and the reflective element will not generally transmit a separately identifiable image of a feature external to the building or structure. One will tend to see just sunlight from the reflective element and no visually discernible image of any external feature. The optical element on the other hand will tend to provide an image of a feature external to the building or structure. It will do so by capturing light reflected from that feature and providing the image for view through an aperture in the light pipe.

It will be appreciated by the person skilled in the art, that any description in relation to the separate aspects of the invention, will also apply to any arrangement of the invention with those aspects combined.

The invention allows for multiple apertures to be provided in the light pipe. This allows for a spread of light throughout the building or structure than can be achieved with conventional light pipes. Conventional light pipes, such as those illustrated by the prior art illustrated above, will generally have only one opening at its lower end to emit light into a room or such like. For example any embodiment of the present invention may include at least one aperture in the side walls and additionally an aperture (of the conventional type) formed by an opening at the lower end of the light pipe. In this way a plurality of apertures may be provided which have a window type appearance. As it is desirable to have a window in any given room etc. this provides a very desirable room arrangement. For example a working area could be placed proximate a "window" to provide a more desirable workspace.

However it is desirable to provide at least two distinct apertures in the sidewall of the light pipe. Preferably a series of apertures are provided circumferentially about the light pipe, so as to allow light to be transmitted into the room at different locations about the light pipe. In such a series and of course depending on the size of the light pipe in question, any where from 2 to 100 or more apertures could be provided. If the aperture is arranged to illuminate a work space such as a working surface, for example a desk area, drawing board or the like, the number of apertures will limited by the required size of such working spaces. Typically 1 to 10 working areas could be illuminated, usually between 2 and 8, for example 2 to 5 such as about 3 on any givep level (a level in this respect is generally the level of a building/structure between the upper boundary (usually a ceiling) and the lower boundary (usually a floor) of any given floor of the building) within the building/structure.

It will be appreciated that, particularly where the light pipe is adapted to illuminate more than one level, it is desirable that the apertures for one level are spaced from those of another level longitudinally along the light pipe. Furthermore it is desirable, particularly to distribute the light available in an acceptable amount to different levels of the floor, to stagger the aperture(s) for one level from that (those) for another. This may be achieved by at least partially, and desirably fully, circumferentially spacing aperture(s) for one level from those of another. In this arrangement there will be only partial or more desirably no overlap. This arrangement has the advantage of avoiding a situation where a lower down aperture is effectively in the shadow of a higher up aperture (because light transmitted through the upper aperture is lost to the lower down aperture) and thus receives a lesser amount of light. The arrangement allows for a more even distribution of light to the apertures.

Higher numbers of apertures may be employed, such as where the objective is to increase the number of light outlets on the light pipe for example for aesthetic, display or other purposes. It will be appreciated that the optical element allows an image of a real feature external to the building or structure to be reproduced inside the building or structure.

The optical element (or image re-direction device) is configured such that an image of a feature external to the building is reproduced inside the building, for example an image of the sky can be reproduced, such as to an observer seated at a desk in a room.

The light pipe of the present invention can be installed into a building when constructing the building or retrofitted to an existing building. The design of the light pipe can be varied depending on the climatic conditions, which influence the level of light available to be captured by the light pipe. For example light available for capture will vary from country to country. Ideally the optical element is positioned substantially adjacent to the aperture in the side wall. Where more than one aperture is provided it is desirable that an optical element is associated with each aperture.

Preferably, the optical element comprises a reflective element. Suitably the optical element comprises partially or fully transmissive material such as glass or a mirror to direct light through the aperture to reproduce said image. In a preferred embodiment, the optical element (image re-direction device) is in a substantially V shaped configuration such as for example a V-shaped mirror. The optical element may be one piece or may be formed of two or more pieces for example, two optical element portions arranged at an angle to each other to provide the common function of providing the image for view.

In another embodiment the optical element is positioned adjacent to a horizontal aperture ledge on the side wall of the conduit such that the image is reflected for view through said aperture (and from the interior of the building). In a further embodiment a plurality of optical elements (image re-direction devices) such as a plurality of mirrors are positioned in the light pipe to allow for capture of an image of a feature external to the building for view through at least two apertures positioned at different levels in the light pipe such that the upper level optical element(s) do not block the view or light transmission to the lower level optical element(s).

Ideally, an adjuster is provided to adjust the level of light transmitted through said aperture. In one embodiment the adjuster changes the effective dimension(s) of the aperture. Suitably the aperture size is slidably adjustable. Ideally, the adjuster slides into the conduit (through the aperture) along a substantially horizontal plane. Adjusting the dimensions of the aperture through the adjuster (screen) may alter the level of light transmitted through the aperture. The adjuster can be manually controlled to alter the amount of light transmitted through the aperture.

In another embodiment the adjuster comprises a mechanism, which automatically adjusts the reproduced image by tracking the path of maximum light throughput a day thereby maintaining the quality of the image and the level of light transmitted into the building.

The light pipe may be constructed so that at least one reflective inner surface is arranged on at least one side wall within the conduit so that light entering the light pipe body is reflected along the conduit toward the aperture. The inner surface may be unitary such as a coating applied to the interior surface of the side walls, or composed of a number of individual elements such as panels.

Preferably, the side walls defining the aperture further comprise at least one reflective inner surface arranged on the side walls so that light entering the light pipe body may be reflected down the conduit towards the other end of the light pipe. In this way light is transmitted about the light pipe and along the light pipe. In another embodiment the light pipe comprises at least three apertures arranged in the same plane around the perimeter of the conduit and substantially equidistant to each other such that light is directed to reproduce the image through each aperture. Suitably at least one aperture is provided at a position on the side wall which is arranged in use to be positioned for providing (natural) light to a work surface such as a desk. In such an arrangement at least one work surface is provided adjacent the light pipe and the light pipe is arranged to provide natural light to the work surface. A user of the work surface will thus be able to work in natural light.

As the reflective element is arranged internally within the conduit it is desirable that it does not interfere to any substantial extent with the ability of the light pipe to transmit light along and about the conduit. Accordingly it is desirable that the reflective element is at least partially reflective on two opposing (for example back to back) surfaces thereon. In this way light incident on for example a front surface can be reflected through an aperture while light incident on a back surface of the reflective element will be reflected along the conduit. Accordingly any potential light barrier by the reflective element is substantially reduced.

Brief Description of the Drawings

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:-

Figure 1 is a perspective view of a preferred embodiment of a light pipe installed in a three floor structure;

Figure 2a is a perspective view of the light pipe installed in a three floor structure; Figure 3 is a part-sectional view of the optical element in place, in which a part- sectional view of the light pipe is also shown;

Figure 4 is a sectional side elevation of a part of the light pipe about an aperture of the light pipe showing how a person within the structure would see the optical element;

Figure 5 is a perspective view of an assembly for use within the light pipe construction;

Figure 6 is an arrangement illustrating a prismatic unit for directing light through the aperture in the light pipe; and

Figure 7 is a sectional side elevation of a prismatic glazing unit for directing light along the light pipe.

Detailed Description of the Drawings

Referring to .Figures 1 , 2a, 2b, 2c and 2d, the light pipe 1 (the light pipe is not structurally part of the building) has a body 18 comprising a sidewall 7 defining a conduit 9. The body 18 has a first end 5 and a second end 6 where the first (upper) end 5 is arranged to capture ambient light (by being arranged to be external to a building or structure 60 - see Figure 1). In Figure 1 the (incident) ambient light is indicated by arrow 50.

The light pipe 1 further comprises a (transparent) dome 3 attached to the first end 5 of the body 18. The body 18 has a raised rim 12 provided on the side wall 7, about the conduit 9. The rim 12 is utilised to retain the dome 3 over a parabolic dish 10 which is arranged internally within the dome 3. The dish 10 acts as a light capturing means or light collector. The parabolic dish 10 is housed inside the dome 3 so that it captures ambient light and is protected from environmental factors. The parabolic dish 10 is pivotably attached at pivot points 19a and 19b to the side wall 7. The parabolic dish 10 may be supported by a frame 11. The frame 11 may be pivotably linked to the pivot points 19a and 19b. The position of the parabolic dish 10 relative to the dome 3 can be adjusted by movement (actuation) of the frame 11. The frame 11 may be manually or automatically moved through about 180° such that the dish 10 may be moved from the position shown in Figure 2a to a position where the dish 10 is substantially facing the opposite side of the dome 3. For example such movement is desirable so that the dish 10 "tracks" the movement of the light source (sun) which varies depending on the time of day and the time of year. Movement between the two positions is illustrated by arrow 22.

Referring to Figure 2b, the second (lower) end 6 of the body 18 comprises a transparent diffuser 21 for emitting light into the internal space of a building in manner conventional to light pipes as illustrated by arrow 51. A light source in the form of a powered (e.g. electric) lamp 8 is housed in the conduit 9 towards the second end 6 of the body 18 which can provide light when it is dark (or when there is a low level ambient light that can be captured by the parabolic dish 10) by illuminating the conduit 9 of the light pipe 1.

A plurality of apertures 4 are defined in the side wall 7 of the body 18. As best seen for Figures 1 , 2c and 2d in a preferred embodiment, three apertures 4 are located in the light pipe 1 on each level of the building in which the light pipe 1 is located, with the exception of the lowest (ground/basement) level of the building which in some embodiments will only have one light diffuser 21 located in the ceiling. In the embodiment shown the building structure 60 has three levels - a basement level 61 ; a first floor 62 and a second floor 63. The dome 3 is external to the building 60 being arranged to extend beyond the roof level of the building, while apertures 4 are arranged in threes on each of the two floors 62 and 63. The diffuser 21 is arranged to emit light from the end 6 of the light pipe into the basement 61. The apertures of the light pipe are circumferentially spaced about the perimeter of the conduit/sidewall, and as seen the apertures are (circumferentially) offset from each other between floors 62 and 63 so as to maximise light output through the apertures. Each aperture 4 is configured so that a desk or working area 2 can be positioned in close proximity to the aperture 4 such that the working surface of the desk 2 is substantially horizontal with the bottom edge of the aperture. In this way a window type effect is achieved with the apertures 4. Referring to the Figures the optical element (image re-direction device) comprises at least one piece of partially or fully transmissive glass or a mirror, (in the embodiment a v-shaped mirror 15 is employed) which, in the embodiment shown is attached to the side wall 7 defining the conduit 9 at a position below the (horizontal) level of each working area or desk 2. The mirrors 15 are additionally below the (horizontal) level of the bottom edge of each aperture 4. The mirrors 15 are each constructed of two separate mirror portions 15a and 15 b which together form a capture area (reflective surface area) of the combined surfaces 15c and 15 d.

As can be best seen from Figures 3 and 4 the mirrors 15 are each angled away from the horizontal (indicated by line C). In particular, in the embodiment shown, the mirror portion 15b is angled away from the horizontal by about 30 degrees (see arrow A) while the mirror portion 15a is angled away from the horizontal by about 105 degrees (see arrow B). In this position the mirrors 15 are arranged to capture an external object and reproduce the image for view within the internal space along the line of sight (indicated by lines D) of a person 35 sitting at a desk 2 will be able to see the image through the transparent or translucent screens 16 across each aperture 4. Part of the image is seen as an (imaginary) image on each of the portions 15a and 15b of the mirror 15. Having the optical element with two portions arranged at an angle to each other is particularly useful to allow the image to be viewed from a position below normal eye level. If desired the screen 16 may be divided by function - a lower part 16a through which the image is viewed and an upper part 16b which is mainly to transmit light. The overall effect therefore is to give the illusion that the screen 16 on each aperture 4 is more akin to a window than an artificial light source. Each aperture 4 has running radially inwardly therefrom opposing side walls 17. The sidewalls 17 run from the aperture 4 radially inwardly to meet with a reflective element 60. As will be seen from the Figures (best seen from Figures 2c and 2d) the reflective elements 60 are generally of the same dimensions and shape as the apertures 4. Being spaced (radially inwardly) from aperture 4 and being positioned within the conduit, each reflective element 60 is arranged so as to reflect light from within the light pipe through the aperture. The side of the side walls 17 facing into the duct (see Figure 5) have been labelled 17a and are made of a reflective material so as to increase the amount of light that is passed through the light pipe 1 to illuminate lower levels of the building. By making the sidewalls reflective substantially less light travelling within the conduit is blocked or adsorbed by the sidewalls. The rear surface 60a of the reflective element 60 is reflective (again to maximise light transmitted along the light pipe) as is the front surface 60b so as to reflect light as set out above (again see Figure 5).

The (surface) side of the side walls facing towards each other (labelled 17b in Figure 5) is of a bright but not fully reflective surface so that light can be passed through the screen 16 and into the room or level but minimising glare of the light. In use the optical element 15 (image re-direction device) is located below the line of vision of a person 35 standing or sitting at the desk 2. For example, the person 35 sitting at the desk 2 can look along arrow line of sight D (Figure 4) to view the image.

It will be appreciated that the side walls 17 and the reflective element 60 together form a trap to catch light and direct it to the aperture 4. The trap so formed does not have a closed top or closed base (both are open) so that light can enter and exit the trap in this way.

The amount of light that enters the internal space of a building through the aperture 4 can be adjusted by manual or mechanical means by altering the (light transmitting) dimensions of the aperture 4. For example a shutter may be provided which will block light entering the aperture 4, to a desired extent. Generally the position of the shutter will be selectable in the range of positions from the fully obscuring the aperture (fully closed) to not obscuring the aperture (- fully open). The shutter could be arranged behind the screen 16 but desirably is external to the light pipe 1.

As can be seen from Figure 4, the reflective element 60 can slidably move in the direction of the arrow E in a radial direction. For example the reflective element 60 can be moved further into the conduit 9. Alternatively it can move closer to the aperture 4. In this way the amount of light transmitted through the aperture 4 can be adjusted. It will be appreciated that the closer the reflective element 60 is to the aperture the less light it will catch from the light pipe and the lower the amount of light transmitted. Conversely the further the. reflective element is from the side wall/aperture the greater the amount of light it can transmit. In this way providing an adjustment mechanism for adjustment of the relative position of the reflective element 60 to the aperture/sidewall is desirable to allow for adjustment of the amount of light transmitted.

When the aperture 4 is fully open (the full dimensions of the aperture are available to transmit light) more light will enter the internal space of the building compared with when the aperture is partially open. When all apertures are in the fully open position, the light level reaching all desks in the building will generally be roughly equal. For this reason the upper apertures 4A will have a maximum slide open position less than the maximum slide open position of the apertures at lower levels 4B. The apertures can be individually adjusted to a fully closed position if the person(s) 35 is experiencing discomfort from light glare or such like.

Alternatively or additionally the configuration of the optical element (image re- direction device) is adjustable so that the correct positioning of the optical element (image re-direction device) can be achieved for persons 35 of different heights. It is desirable that optical element (image re-direction device) is below the line of vision of the standing or seated person 35 otherwise the person 35 would see their own reflection in the aperture 4 and may be dazzled by glare from the transmitted light. A desk 2 may also be located below the diffuser 21. This arrangement provides for light to be directed into the internal space of a building and provides desktop lighting.

The elongate body 18 of the light pipe 1 will be of suitable dimensions to fit into the building in which it is to be installed. Typically, the elongate light pipe body 18 will have a length in the range of 3 to 6 meters (for two and three floor buildings) respectively and will have a diameter in the order of 500 to 1000 mm depending on geographical region and number of floors served. For example a light pipe 1 6m in length and 1m in diameter can typically be used to provide natural light to three levels. However, the exact dimensions of the light pipe 1 will ultimately depend on the dimensions of the building or structure and the area to be illuminated. The light pipe material can be made from light grade aluminium with a highly reflective surface finish or other suitable material.

In a preferred embodiment, the light pipe 1 comprises at least one reflective inner surface arranged on the at least one side wall 7 within the conduit 9 so that light entering the light pipe body 18 is reflected along the conduit toward the aperture 4, 21. The use of a reflective inner surface will amplify the light as it passes through the conduit 9 providing a brighter light through the aperture(s) 4, 21. The reflective inner surface can be provided by a mirror or prismatic glazing or a combination thereof. For example the reflective inner surface finish may be a 97 per cent or greater specular reflective material and can be applied as a film coating such as from commercially available film sheets or as part of the light pipe manufacturing process such as by way of surface finishing and/or by application of a reflective metal surface.

It will be apparent to a person skilled in the art that the reflective surface can be integral with the at least one side wall 7 defining the conduit or that the reflective surface can be retained by any known means of attaching/securing/coupling for example bolting or adhering a reflective surface that contacts or is adjacent to with the at least one side wall 7 defining the conduit 9. The first end of the light pipe body 18 can be arranged to capture light. The light will usually be light from outside the building and can be natural daylight or artificial street lighting or such like. For example the first end 5 may be positioned with access to the exterior of the building. In one embodiment the light pipe 1 is arranged such that the first end 5 is incorporated into the roof of the building. The first end 5 can be retained in position by one or more retainers as with conventional roof or sky lights by fixing bolts onto a supporting frame which will take the main weight of the light pipe 1. The supporting frame rises a distance above the roof level to realise a maximum field of view with minimal obstructions to the direct sunlight.

The first end of the dome 3 comprises a cover that desirably seals the first end from the external environment and prevents dust, water and debris and the like from entering the light pipe. The cover can be constructed form a material that allows light to enter the light pipe whilst being tough enough to withstand environmental forces such as wind and rain and hail stones and the like. Suitable materials are glass or plastics such as transparent (in particular) amorphous polymers for example polypropylene or polyethylene. It will be apparent to a person skilled in the art to select the material most suitable for the environment to which the sealing means is exposed. For example, polyethylene for use in warm climate regions thereby allowing egress of long wave radiation at night from the building or glass in temperate to cold climate regions to re- reflecting long wave radiation into the building at night minimising heat losses.

The cover has three functions:

(i) allowing light to enter the dome 3;

(ii) concentrating the light before it enters the light pipe 1 ; and (iii) illuminate the interior of a building at night via alteration of the position such as from vertical to horizontal so that the light cover carries out the functions of (i) and (ii) above with respect to an artificial light source 8. The artificial light source 8 can be positioned anywhere in or near the light pipe 1.

The light cover may comprises one or more of each of mirrors and lenses 10, such as a fixed reflective parabolic disc, a plane mirror heliostat, or a mechanised sun tracking prismatic heliostat. The cover should be of sufficient dimensions to capture the desired level of light (usually a maximum amount). For a parabolic dish, described above, suitable dimensions for a 1000 mm diameter light pipe 1 are of the order 800 mm high and 500 mm radius. The person skilled in the art will know that the dimensions of the light capturing means are intimately related to the dimensions of the light pipe 1 and will be in a position to optimise performance of the light pipe 1 for a given building or structure.

The cover can additionally be a stationary passive collector system that relies on the optics of the dome 3 to capture and transmit light into the light pipe. Preferably, the dome 3 tracks the path of maximum light thereby being positioned at the correct angle to maximise the amount of light the dome 3 is exposed to. _^ The actuation means can be manual or automatic or a combination of both. For example, manual actuating means comprise a cable attached to the light capturing means that allows for rotation of the light capturing means through a system of pulleys, gears, weights, or a combination thereof. Whereas automatic actuating means may for example comprise a motor to provide the necessary torque required by actuation or rotating the light capturing means through a system of pulleys, gears, weights, or a combination thereof.

The second end 6 of the light pipe body 18 is generally spaced away from the first end 5 and comprises a light outlet 21. The second end 6 is positioned so that light can be transmitted into an internal space of a building, typically the second end 6 will be arranged for location in the ceiling of an internal room. Depending on the dimensions of the light pipe 1 the second end 6 may be located in the ground floor ceiling although it will be apparent to those skilled in the art that the light pipe 1 can be of dimensions to accommodate the placing of the second end 6 into a basement or first floor or second floor or the ceiling. The second end 6 is secured into place with fixing means such as bolts or screws onto a frame housing within the ceiling layout as used in conventional luminarie housing fittings or in sky light internal domes.

The function of the aperture 4 is to provide an outlet for the light. In a preferred embodiment the at least one side wall 7 defining the conduit 9 is substantially cylindrical, it will however be apparent to a person skilled in the art that the at least one side wall 7 could define a conduit 9 of a different shape for example elliptical, rectangular, triangular, square, planer, parabolic, hyperbolic, or a hyperbolic parabolide. Desirably the conduit 9 will have an internal diameter of 300 mm to 1 ,500 mm, for example 400 mm to 1 ,200 mm such as 530 mm to 1000 mm.

In another embodiment the light pipe 1 has a number of apertures 4 along it's length that correspond to the number of floors to be illuminated in the building for example in a three floor building in addition to the second end 6 of the light pipe 1 there would be apertures 4 located at each floor to provide light to the same level of a building. This arrangement will typically halve the required artificial lighting required in a building for 10 to 70 % of the year for example 15 to 60% such as 20 to 50%.

The dimensions of the aperture 4 are intimately linked with the dimensions of the light pipe 1. Preferably the aperture is 100 mm by 1000 mm for example 150 mm by 900 mm such as 250 mm by 800 mm. It will be obvious to a person skilled in the art that the dimensions of the aperture 4 can be varied depending on the dimensions of the light pipe 1 , the amount of apertures 4 and light it is desired to have and the layout of the building.

In a further embodiment the present invention provides an adjustable aperture 4 whereby the level of light entering the internal space of a building can be controlled by a mechanism altering the dimensions of the aperture(s) 4. The dimensions of the aperture 4 can desirably be adjusted by lateral or vertical means. Desirably the side wall(s) 17 defining the aperture 4 slide(s) into the conduit 9 of the light pipe 1 along a substantially horizontal plane. Even more desirably, the side wall(s) 17 slide lateral into the conduit 4 thereby altering the dimensions of the aperture while retaining the size of the viewing area in the building. In a preferred embodiment the side walls 17 defining the aperture 4 slides into the conduit 9 along a substantially horizontal plane for a distance of about 0 mm to 800 mm for example 0 mm to 700 mm such as 0 mm to 500 mm.

In another embodiment the sliding aperture 4 is defined by the side wall 7 defining the conduit 9 with the reflective side facing into the conduit 9. In a different embodiment the aperture 4 may be defined by at least one side wall 17. The side wall(s) 17 can be formed from the same material as the side wall 7 of the light pipe body 18 to increase the level of illuminance directed into the building. The side wall(s) 17 of the aperture 4 can define an aperture 4 of any suitable shape but typically the aperture 4 may be substantially square, rectangular, circular or oval but not limited thereto.

The dimensions of the aperture 4 can be adjusted manually by the end user to control the level of illuminace in the building by a control mechanism, for example by a lever or a handle or a crank or pulley system. The dimensions of the aperture can also be controlled by mechanical means for example by use of a motor that provides torque to open/close the aperture by way of a gear connected to a handle or a crank or pulley system, or connected to a boom attached to the side wall 17 defining the aperture 4, with gear teeth to allow motion of the side wall 17 defining the aperture 4 toward or away from the light pipe side wall 7.

One of the advantages of a light pipe 1 according to the present arrangement is that rather than just providing light into a room in a building the light may be directed into a number of locations within the building and a number of different locations within the same level of the building. The advantage of this type of arrangement is that a number of aspects on a given level of the building are illuminated with light. It is therefore a way in which a room can be provided with a level of light that is typically only obtained in dual-aspect or multi-aspect rooms. The effect of having a location that is brightly illuminated through light as opposed to artificial light is that the location such as a room or office or level of a building feels larger and airy and is thus more attractive to its occupants. The overall mood of the occupants may be improved.

The optical element (image re-direction device) include any means that reflect or refract light such as but not limited to mirrors, lenses, prisms, prismatic glazing, reflective elements or specular elements, or any combination thereof. The reflection of light is the change of direction in a light beam at an interface between two dissimilar media so that the light beam returns into the medium from which it originated and refraction is the deflection or bending of light at the interface between different media and where the refraction of a beam of light depends on the refractive index of the material. The optical element (image re-direction device) can be a flat, concave or convex mirror or lens, a prism such as a block of optical material with flat polished sides arranged at precisely controlled angles to each other, which deflect, deviate and rotate beams of light as well as dispersing their wavelengths or combinations thereof. There are many types of prism known in the art which each have a particular geometry in order to achieve the reflections necessary to perform a specific imaging task. For example reflecting prisms may invert, rotate, deviate or displace a beam of light. It will be apparent to a person skilled in the art which optical element (image re-direction device) to utilise in each specific light pipe.

Figures 6 and 7 illustrate a prismatic glazing unit for directing light through the aperture 4, indicated generally by the reference numeral 30. Prismatic glazing may be used to enhance downward light transmission onto the working plane from the light pipe aperture. This is permissible through the arrangement of prismatic glazing unit mounted to hinge 31 into or away from the aperture opening. The glazing unit can pivot about this hinge toward or away from the duct aperture opening for a maximum tilt angles of -45° away from the aperture opening into the room (whereby the upper edge of the prismatic glazing is opened toward the occupant/working plane) or +15° (whereby the prismatic glazing unit is opened outwards towards the aperture opening into the duct, moving away from the occupant) arrow F. The light rays reflected within the light pipe will vary in angle of inclination between a maximum of 15° in winter to 60° in summer. 'Siteco' prismatic glazing unit 42° (arrow G) by 5° (arrow H) prisms for example in the upright position (0°) shown in Figure 7 with the plane edge parallel to the duct wall and the near horizontal prism edge (5°) parallel to the working plane and the remaining 42° angled prism face facing away from the working plane will refract 30° incident rays of light from the duct to an angle of 36° to the working plane. The rays entering the prismatic glazing are partially from the duct wall and partially from the aperture movable wall which is also a mirror finish on both sides for application with prismatic glazing only. To adjust this unit through inclined angle-of -5° to horizontal (outwards from the duct toward the occupant) will refract the rays more downward to 57° to the horizontal; whereas adjusting the unit to an angle of 5° in opposite direction results in total internal reflection reducing substantially light transmission. The prismatic unit 30 is mounted on a hinge 31 into or away from the aperture 4 opening. The height of the hinge base is determined by the view height required to allow a view to the sky or ^{^}outside view from the optical means. The aperture side walls are arranged to follow the side profile generated by the prismatic glazing unit projection into the occupied space. The viewing portion of the aperture below the pivot level is glazed with standard clear glass and affords a view to the sky or some outside view through the optical means. The prismatic unit 30 can pivot about a pivot point such as hinge 31 either away from the aperture 4 opening for a maximum tilt angles of minus 45 Degrees (arrow F) away from the aperture 4 opening into the room, whereby the upper edge of the prismatic glazing 30 is opened or towards the aperture 4 opening plus 15 Degrees (arrow F) whereby the prismatic glazing unit 30 is opened outwards towards the light pipe 1. The light rays 34 reflected within the light pipe 1 will vary in angle of inclination depending on what type of light view is required. The prismatic unit 30 comprises a number of prisms 33. The light rays entering the prismatic glazing unit 30 are partially from the light pipe wall 7 and partially from the aperture movable wall 17 which also can have a mirror finish. The prismatic unit 30 can be adjusted through an inclined angle of minus 5 Degrees outwards from the duct as illustrated in Figure 6, which has the result of refracting more light out of the aperture 4. Conversely, adjusting the prismatic unit 30 to an angle of 5 Degrees in the opposite direction results in total internal reflection reducing substantially light transmission. The height of the hinge 31 is determined by the view height required to allow a view of a feature external to the building via optical means (image redirection devices). The aperture side walls 17 are arranged to follow the side profile generated by the prismatic glazing unit 30 projection into the occupied space. The viewing portion of the aperture 4 below the pivot level is glazed with standard clear glass and affords a view of a feature external to the building through the optical element (image re-direction device).

In another embodiment of the present invention the optical element (image re¬ direction device) comprises a substantially V shaped mirror 15, however it will be obvious to a person skilled in the art that any suitable shape optical means can be used such as L-shaped, U-shaped and the like. In the present invention the V shaped mirror 15 may comprise of two mirrors (connected a profiled aluminium angled support frame to retain the position of the mirrors) in a substantially V shape for example the point of the V is at an angle of 10 degrees to 170 degrees for example 20 degrees to 140 degrees such as 30 degrees to 105 degrees.

In a further embodiment the mirror 15 is positioned so that it is substantially contiguous with the horizontal aperture ledge located furthest away from the first end of the light pipe 1 and angled so that the mirror 15 can reflect an image such as an image of a feature external to the building into the interior of the building. The position of the mirror 15 can be staggered to allow for optimum or maximum capture of an image of a feature external to the building for view through the aperture 4. That is, the mirrors 15 placed within the conduit 9 are positioned in a staggered layout such that the upper mirrors do not infringe on light/view transmission to the lower mirrors. An additional light source 8 such as a metal halide, halogen, florescent, compact florescent, tungsten filament, or sodium lamps, or any combination thereof maybe positioned in the conduit above the second end 6, so that the light emitted from the light source 8 is directed towards the first end 5 of the light pipe 1. The light capture means 21 located adjacent the first end 5 changes from its vertical to a horizontal position in which the light capture means 21 covers for example 75 per cent of the first end 5. This affords the reflection of the additional light source 8, thereby providing illumination during night time and maintaining the reflection of the external image into the interior of the building. The actuation means can be manual or automatic or a combination of both. The manual actuating means may comprise a cable attached to the cover that allows for rotation of the light capturing cover through a system of pulleys, gearβ, weights, or a combination thereof.

The light pipe 1 of the present invention will give the illusion that the aperture 4 is actually a window as the image that the occupants 35 will see will be a real time image. This will improve the atmosphere in the building as the occupants 35 of for example deep plan buildings will not feel confined from the outside world as they will be able to see the image, for example the sky, in real time and will be able to notice the change in for example weather, daylight and seasons from the interior of the building. Furthermore, the light pipe 1 will also provide sufficient daylight during the working year to meet task lighting needs at for example an occupants 35 working desk 2.

It will be appreciated that certain features of the invention, which are, .for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub- combination.

The words "comprises/comprising" and the words "having/including" when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

The invention is not limited to the embodiments hereinbefore described but may be varied in both construction and detail.

Claims

1. A light pipe for transmitting light internally into a building comprising:

(i) an elongate light pipe body having a first end arranged to capture light and a second end spaced therefrom and at least one side wall defining a conduit;

(ii) an aperture in the side wall between the first and second ends; and, (iii) at least one optical element positioned within the conduit and arranged so as to reproduce an image of a feature external to the building for view through the aperture.

2. A light pipe according to claim 1 further comprising at least one reflective inner surface arranged on the at least one side wall within the conduit so that light entering the light pipe body is reflected along the conduit toward the aperture.

3. A light pipe according to claim 1 or claim 2 further comprising a light collector for capturing ambient light and directing the light into the light pipe body.

4. A light pipe according to claim 3 wherein the light collector can be moved to track movement of ambient light.

5. A light pipe according to claim 4 wherein the light collector automatically tracks movement of ambient light.

6. A light pipe as according to any one of the preceding claims wherein the optical element is positioned substantially adjacent to the aperture in the side wall for reproducing an image for view through the aperture.

7. A light pipe according to any one of the preceding claims wherein the optical element comprises a reflective element for reflecting an image.

8. A light pipe according to any one of the preceding claims wherein the optical element comprises a mirror to direct light through the aperture to reproduce said image.

9. A light pipe according to claim 8 wherein the optical element comprises a substantially V shaped mirror.

10. A light pipe according to claim 8 or claim 9 wherein the mirror is positioned adjacent to a horizontal aperture ledge on the side wall of the conduit such that the image is reflected through said aperture.

11.A light pipe according to any one of claims 8 to 10 wherein a plurality of the rrjirrors are positioned in the light pipe to allow for capture of an image of a feature external to the building for view through at least two apertures positioned at different levels in the light pipe such that an upper level mirror does not block the view or light transmission to a lower level mirror.

12. A light pipe according to any one of the preceding claims comprising an adjuster to adjust the level of light transmitted through said aperture

13. A light pipe according to claim 12 wherein the adjuster is slidably adjustable.

14. A light pipe according to claim 13 wherein the adjuster slides towards the centre of the aperture along a substantially horizontal plane.

15.A light pipe according to any preceding claim wherein the optical element can be adjusted to alter the amount of light transmitted through the aperture or apertures.

16. A light pipe according to claim 15 wherein the position of the optical element can be adjusted to alter the amount of light transmitted through the aperture or apertures.

17. A light pipe according to claim 14 wherein the mirror can be adjusted to alter the amount of light transmitted through the aperture.

18. A light pipe according to any one of claims 12 to 17 wherein the adjuster can be manually controlled to alter the amount of light transmitted through the aperture.

19. A light pipe according to any one of claims 12 to 17 wherein the adjuster comprises a shutter adjacent the aperture.

20. A light pipe according to claim 19 wherein the shutter is actuated such that it can slide in and out of the body of the light pipe thereby adjusting .the djmensions of the aperture.

21.A light pipe according to claim 20 wherein the body of the light pipe further comprises at least one stop to limit the sliding in and out the shutter with respect to the light pipe body.

22. A light pipe according to any one of claims 12 to 21 wherein the adjuster comprises a mechanism which automatically adjusts the reproduced image to track levels of light throughout a day to maintain the quality of the image and light transmitted.

23. A light pipe according to any one of the preceding claims wherein the side walls defining the aperture further comprise at least one reflective -inner surface arranged on the side walls so that light entering the light pipe body is reflected down the conduit towards the other end of the light pipe.

24.A light pipe according to any one of claims 12 to claim 23, wherein the adjuster comprises a pane of light transmissive material portioned across the aperture.

25. A light pipe according to claim 24 wherein the pane can be utilised to change the direction and/or intensity of the light transmitted from the light pipe.

26.A light pipe according to claim 25 wherein the pane comprises prismatic glazing.

27. A light pipe according to any one of claims 24 to claim 26 wherein the pane of light transmissive material is arranged so that it can change the direction of the light so that substantially all of the light entering the aperture is directed downwardly.

28. A light pipe according to any one of claims 24 to claim 27 wherein/the angle of the light transmissive material to the light pipe can be adjusted to change the direction and/or intensity of the light.

29.A light pipe according to any one of the preceding claims wherein the optical element assists in maintaining the required illuminance level through the aperture.

30. A light pipe for transmitting light internally into a building comprising: (i) An elongate light pipe body having a first end arranged for capturing light and a second end spaced therefrom and at least one side wall defining a conduit;

(ii) an aperture in the side wall between the first and second ends; and,

31.A light pipe according to any one of the preceding claims wherein the light pipe comprises at least three apertures arranged in substantially the same plane around the perimeter of the conduit and substantially equidistant to each other such that light is directed to reproduce the image through each aperture.