WO1997031276A1 - A light-diverting optical element - Google Patents

A light-diverting optical element Download PDF

Info

Publication number
WO1997031276A1
WO1997031276A1 PCT/GB1997/000517 GB9700517W WO9731276A1 WO 1997031276 A1 WO1997031276 A1 WO 1997031276A1 GB 9700517 W GB9700517 W GB 9700517W WO 9731276 A1 WO9731276 A1 WO 9731276A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical element
light
element
face
cavities
Prior art date
Application number
PCT/GB1997/000517
Other languages
French (fr)
Inventor
Peter James Milner
Original Assignee
Milner Peter J
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to GB9603639.7 priority Critical
Priority to GBGB9603639.7A priority patent/GB9603639D0/en
Application filed by Milner Peter J filed Critical Milner Peter J
Priority claimed from GB9817985A external-priority patent/GB2328239B/en
Publication of WO1997031276A1 publication Critical patent/WO1997031276A1/en

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21SNON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S11/00Non-electric lighting devices or systems using daylight
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21VFUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V5/00Refractors for light sources
    • F21V5/02Refractors for light sources of prismatic shape
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/04Prisms
    • G02B5/045Prism arrays

Abstract

An optical element (12) has two opposite major faces (13, 14), a first (13) of which, intended to be an incident face in use, is formed with a plurality of cavities (16) which extend partway through the thickness of the body (12) of the element. Flat faces (17, 32) formed either between adjacent cavities (16) or as the bottoms of the cavities, lie parallel to the opposite major face (14) of the elements so that light incident on these surfaces, and within certain range of angles, passes through the elements substantially undeviated to provide a view to an observer. Light entering the cavities (16) is refracted and reflected so as to be diverted into a narrower range of exit angles than incident angles thereby concentrating the light. In use as 'daylighting' glazing transmitted light can be concentrated in an upward direction increasing the level of illumination within a room.

Description

A LIGHT-DIVERTING OPTICAL ELEMENT

The present invention relates generally to a light- diverting optical element. Embodiments cf the invention may be suitable for use in enhancing the internal illumination of buildings using daylight. Other embodiments may be used as light-diverting covers for light sources. Hereinafter, without prejudice to the generality of the invention, it will be described primarily in relation to its application as a glazing element.

Traditional glazing of openings in buildings allows the light from outside the building to enter substantially undeviated. Any bright areas in the external environment, therefore, for example the disc of the sun or the higher parts of the sky, give rise to concentrations cf illumination within the rooms into which the light passes through the openings.

In certain circumstances the intensity of the incident illumination in a room from a low angle, for example when the sun is low, can give rise to glare and even dazzling of the room's occupants when looking through an opening, such as a window, or even when just facing towards the window. This can be uncomfortable, inconvenient or even distressing unless some form of shading is available. Because the incident light on the exterior of a building is for much of the time generally brighter and more intense at higher angles of elevation, the maionty of the incident light usually enters the room "ravelling downwards towards the floor. It has long been appreciated that by providing light-diverting optical components as part of the glazing across openings in buildings it is possible to cause the incident light to change direction and be diverted into the room in a direction towards the back wall or ceiling thereby improving the illumination within the room for a given level of external illumination. Early attemp s at such "daylighting" illumination involved the use of prismatic elements and were impracticable for a number of reasons, not least because the light transmitted therethrough was diffused and therefore allowed no view of the outside.

This arises because, the light diversion caused by such elements allowed for no undeviated light transmission. However, the occupants of buildings do not merely require the internal environment to be illuminated, but in general need, or at least prefer, to be able to observe the outside world through the windows. In order to achieve this at least some of the light passing through the windows must, therefore, be substantially undeviated. However, in many prior art "daylighting" systems substantially all the light is deviated either by refraction or reflection to such an extent that any image of the external environment s so diffused as to be indecipherable. The occupants of rooms having windows glazed with such elements would have had no view outside.

Another more recent system is discussed in International Patent Application WO 91/03682. This describes a stacked array of refractors defining an illuminating channel between opposite surfaces of each element of the array. The elements have parallel faces by which adjacent elements are secured together using adhesive. Light entering an incident surface of an element at a relatively low angle of incidence is refracted to an interface and from there reflected to an emergent face through a channel defined in the element. The ratio of undeviated to deviated light is extremely low and the view of the outside world through a window glazed with such a system is still very poor. In GB Patent 2 240 576 an element having narrow slots in an exit face is described. The manufacturing techniques necessary to make such narrow slots make this configuration prohibitively expensive.

The applicant's own earlier International Application PCT/GB 94/00949 also describes an optical component suitable for use in "daylighting" buildings. This comprises two substantially planar elements each having a plurality of elementary surfaces formed on one face, respectively an inner and an outer face of a cell formed by the two elements. The elementary surfaces are effectively defined by grooves formed on the face of each element, and the elements may be supported on a substrate such as a flat glass panel or may be secured together so as to be self-supporting. The use of two matched elements, adhered together, produces an extremely effective daylighting element, but at some cost disadvantage due at least in part to the need for two elements. This system does however offer an outside view by allowing a proportion of the incident light to be transmitted through undeviated.

The present invention seeks to provide a single element which can act both to allow light within a range of incident angles close to the normal to a general plane of the element to pass through the element substantially undeviated (thereby providing a view through the element) whilst light incident at greater angles of elevation (namely from higher in the sky) is deviated.

According to the present invention, therefore, there is provided an optical element comprising a transparent body having two substantially parallel major faces one of which is interrupted with a plurality of cavities defining a plurality of interfaces at which light incident thereon over a certain range of angles is reflected by total internal reflection, characterised in that at least some of the light incident on the said body is substantially undeviated in its transmission through the body, in that the said one face of the element in which the cavities are formed is intended in use to face a source of light, and in that the width of the cavities is such that at least a substantial proportion of the light incident on the said one face enters the said cavities.

The present invention has the advantage that, because light entering the cavities is "useful" light in that it is transmitted through the element in desired directions, the cavities can be relatively wide in relation to their depth (in particular, of the same order of magnitude) thereby facilitating its manufacture.

It is of great interest in "daylighting" buildings, to be able to divert light incident at a steep angle to the horizontal, that is from high in the sky, away from its downward path, preferably to an upward path so that this light, upon entering the building, is directed towards the ceiling or an upper part of a back wall of a room. At the same time it is desirable to avoid glare from high intensity light incident from a low angle which may arrive directly at the eyes of an observer.

It is also of interest to be able to vary the behaviour of incident light at different angles of elevation. For this reason, in embodiments of the invention the said cavities are preferably formed as elongate grooves in the said first surface of the element. Such grooves are preferably orientated horizontally so that the angle of elevation is changed as light travels through the element, whereas the direction of incidence is relatively less influential.

Alternatively, however, the cavities may be formed as pits or depressions so that both the angle of elevation and the direction of incidence both influence the diversion of the light as it passes through the element. For example, if the element were used as a cover for a light source this would allow light emanating from the light source to be diverted in selected directions as well as elevations.

In embodiments of the invention formed with parallel grooves constituting the said cavities these may be defined by at least two side walls and the maximum groove width, namely the maximum separation between the groove walls, is preferably not less than the separation between adjacent grooves. This allows relatively wide grooves to be formed, simplifying the manufacturing process.

The said substantially laminar element may be a unitary element of flexible material adapted to be supported on a face of a substantially planar support element. In such an embodiment the element may be made, for example, from a transparent plastics material which is not self- supporting. It may for example be made as a relatively thin film suitable for attachment to the internal surface of a flat pane of glass. The attachment may be achieved by filling the cavities with a suitable transparent adhesive which constitutes the said surrounding medium, or the attachment may be made by adhesive applied only between the contacting surfaces of the body and the planar support element, in which case the said surrounding medium may be air or other gas filling the cavities. An element may alternatively be supported at its exit face on the front face of a support such as a flat pane of glass, typically the "inner" pane of a double glazing cell.

Other production techniques, may be employed, however, either to form the body as a substantially rigid self- supporting component, or as a plurality of juxtaposed or connected elementary parts, conveniently in the form of elongate strips stacked with interfaces substantially transverse major surfaces defined by assembled elements.

Regardless of whether the cavities are formed as individual pits or elongate grooves, each cavity may be defined by surface elements which may be flat or curved. Preferably, at least some of the cavities have at least one wall composed of at least two substantially planar wall elements inclined at a non-zero angle to one another. Individual pits may be formed as short grooves with longitudinally adjacent grooves being offset or staggered in relation to one another.

If the cavities are formed as elongate grooves in the said first surface of the element at least some of them may have a groove bottom constituted by the intersection of the groove side wall elements, or by the intersection of a groove side wall element with a groove side wall. In other words, the groove may be substantially V-shape and although, because each groove is defined by three wall elements, only one may be a substantially planar wall, the bottom of the groove is effectively a line defined by the intersection of two faces. These faces may be plane faces or curved faces and the curvature may be convex or concave.

In an alternative embodiment, however, at least some of the elongate grooves in the incident surface of the body may have a substantially flat bottom wall. In such embodiments the separation between adjacent grooves may be reduced to zero so that the incident surface of the body is constituted in effect by a plurality of lines defined by the intersection of the side walls of adjacent grooves. In such an embodiment the adjacent grooves are effectively contiguous.

In a further embodiment of the invention at least some of the elongate grooves in the said body have a bottom wall defined by two surfaces inclined to one another at a reflex angle. This form of groove has particular advantages in allowing a greater width without loss of diverted light since the two surfaces of the bottom wall inclined to one another at a reflex angle can be considered to constitute a small triangular prism at the bottom of the groove, which further diverts incident light by refraction and reflection as will be described in more detail hereinbelow.

In another aspect the present invention provides an optical element for transmitting light incident over a range of angles and having a plurality of elementary surfaces which result in refraction and/or reflection of the incident light, in which the said elementary surfaces are inclined to one another in groups such that light incident on the element over a first range of incident angles is transmitted therethrough with at least a majority of the light being transmitted within a second range of exit angles, the second range being narrower than the first. Embodiments of the invention may be so formed that the groups of elementary surfaces are elongate facets defining the faces of a plurality of generally parallel grooves in at least one face of the element.

A further aspect of the invention provides a transparent optical element having a plurality of elementary surfaces so arranged that incident light, at least to one side of a normal to the incident surface, at less than a certain threshold angle is reflected at an interface of the element with the surrounding medium, and light incident at angles above the said certain threshold is refracted at the said interface such as to be deflected into incidence with a next adjacent elementary surface at an angle less than the said certain threshold. Embodiments of the invention may be formed so that a plurality of the elementary surfaces together define a plurality of said threshold angles of incidence at each of which a proportion of the refracted light is deflected so as to be below the threshold angle for the next adjacent surface element in the path of the incident light. Likewise the elementary surfaces may be formed as elongate facets defining a plurality of substantially parallel grooves in the incident surface of the component, which extend generally horizontally when the component is in its intended position of use, and those facets defining the generally downwardly facing surfaces of the grooves are inclined to one another at shallow angles such that each said downwardly facing groove- defining surface is downwardly convex.

In such an embodiment the acute angle at which the said two bottom wall surfaces meet is preferably greater than the angle between the two groove walls or the wall surface elements adjacent to the groove bottom. Although the above discussion makes specific reference to the use for daylighting buildings, the present invention may also find utility as a glazing element for an opening in any structure other than a building, in particular a vehicle, a vessel, an aircraft or the like, and the opening may be for the entry of daylight into the vehicle, vessel or aircraft, or for the transmission of light from a light source carried thereby.

Various embodiments of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a cross-sectional view through a portion of a first embodiment of the invention illustrating the paths followed by certain rays of incident light;

Figure 2 is a cross-sectional view of the embodiment of Figure 1 illustrating the paths of rays of incident light arriving at a different angle of incidence;

Figure 3 is a cross-sectional view similar to that of Figure 1, of a second embodiment of the invention;

Figure 4 is a cross-sectional view through a third embodiment of the invention;

Figure 5 is a cross-sectional view through a fourth embodiment of the invention; Figure 6 is a cross-sectional view through a further embodiment of the invention;

Figure 7 is a cross-section through a modified embodiment of the invention showing the paths of certain rays through the embodiment; and

Figure 8 is a cross-section through the same embodiment as in Figure 7, but showing the paths of different incident light rays.

Referring now to Figure 1 the embodiment shown comprises a unitary transparent body generally indicated 11 by which enhanced daylighting performance is achieved by ensuring that a substantial proportion of the light incident from higher angles of elevation is reflected towards the ceiling of a room having an opening across which the optical component 11 is fitted. In this embodiment the optical component 11 is intended to be secured to the inner or exit face of a supporting pane of glass 15, although the glass itself has no influence on the diversion of light and it would be possible for embodiments of the invention to be produced in such a way that they are self-supporting.

The optical component 11 comprises, as mentioned above, a single unitary transparent body 12 having an incident surface generally indicated 13 and an exit surface generally indicated 14, and in this embodiment the incident surface 13 is in contact with one face 15 of a supporting pane of glass shown in broken outline in Figure 1. Typically the thickness of the body 12 may be in the region of 1-1.5 mm, perhaps less, whilst a supporting pane of glass may be typically in the region of 4 mm or more for which reason only the rear face 15 of the glass is shown.

The incident surface 13 is interrupted by a regular array of parallel elongate grooves 16 which are all identical or similar in form and the configuration of only one of which will therefore be described in detail . Between the grooves the surface 13 is defined by co-planar elementary faces identified by the reference numeral 17. Each groove 16 is defined by two opposite side walls 18, 19 inclined to one another, of which the side wall 18 is the downwardly facing upper side wall of the groove in the orientation shown, with the grooves 16 being substantially horizontal, the side wall 19 being the upwardly facing lower side wall of the groove 16.

Each groove 16 has a groove bottom 20 defined by two inclined groove bottom wall elements 21, 22 of which the groove bottom wall element 21 is an upwardly facing upper surface (in the orientation shown) and the groove bottom wall element 22 is a downwardly facing lower surface. The upper groove bottom wall element 21 is inclined so as to face outwardly as well as upwardly whilst the lower groove bottom wall element 22 is inclined so as to face outwardly as well as downwardly.

The two groove bottom wall elements 21, 22 meet at an apex 23 and the boundaries of the groove bottom 20 are defined by the linear intersections of the respective groove upper side wall 18 with the adjacent upper bottom wall element 14 (to form an upper fundus 24) and the intersection between the groove lower side wall 19 with the lower bottom wall element 22 (to form a lower fundus 25) . The two groove bottom wall elements 21, 22 meet at a reflex angle the corresponding internal angle of which is greater than the angle between the groove side wall and the groove bottom wall which meets it .

In use of the optical component described above, with the component occupying a substantially vertical orientation, light incident on the elementary faces 17 or lands of the incident surface 13, at an angle of incidence less than a predetermined threshold angle, is transmitted directly through the component without deviation as shown in Figure 2 by the light rays A and B. The threshold angle lies above and below the horizontal plane which is normal to the elementary faces or lands 17 so as to encompass the majority of the field of view of interest to an observer within the room.

As can be seen in Figure 1, light incident on the elementary faces 17 at an angle greater than the threshold angle, as represented by the light rays D and E of Figure 1, are refracted upon passage through the elementary incident surface 17 and reflected upon arrival at the upper side wall 18 of the immediately underlying groove 16. After reflection the light rays then travel through the body of the optical element and exit through the exit face 14 at a slight upward inclination.

Light above the threshold angle which falls on the element 12 between two elementary faces 17, that is light which enters a groove as shown by the light rays F, G and H in Figure 1, are first refracted at the interface defined by the lower side wall 19 of the groove and then refracted again when they pass through the interface defined by the upper side wall of the next lower groove. Upon refraction the light is directed to the upper bottom wall face element 21 at which it is refracted and, thereby, diverted towards the lower bottom wall element 22 of the groove. At the interface defined by the lower bottom wall element the light is reflected, as shown in Figure 1, to pass through the body 12 of the element and out through the exit face 14 in an upwardly inclined orientation. The prisms at the bottom of each groove therefore effectively "sweep up" any light entering the body 12 other than through the elementary faces 17, and which would in their absence be transmitted in a generally downwards direction upon passing through the exit face 14. Although not shown, it would be possible to form these prisms with facets inclined to one another rather than the single face shown in Figure 1.

As can be seen in Figure 2 , for an observer viewing the outside through the element 11 and looking substantially horizontally, about 50% of the eye's viewing area admits light from the outside substantially undeviated, while most of the remainder of the viewing area contains light that originated inside the room. As the room is relatively dark compared with outside objects the view of the outside is substantially unaffected by light reflected back into the room, this light being of much less intensity than the transmitted light. Light rays, such as ray J which result from the reflection of light incident on the element 11 from within the building, is relatively less bright (or intense) and does not contribute much to the image seen by the eye.

Referring now to Figure 3, the general configuration of the optical element is generally the same as that in the embodiment of Figures 1 and 2, and accordingly the same reference numerals have been used to identify the same components or those which fulfil the same function. In this embodiment, however, the lower side wall 19 of each groove is substantially perpendicular to the plane defined by the elementary faces or lands 17 of the incident surface whilst the upper side wall of each groove has two elementary faces or facets, namely an "inner" facet 26 which, like the groove side wall 19 is orthogonal to the plane defined by the elementary faces 17 of the incident surfaces, and an inclined "outer" facet 27. The term "inner" as used herein to describe the positions of groove side wall facets will be understood to mean facets located more deeply into the groove, while the term "outer" will be understood to refer to positions closer to the mouth of the groove. The light rays D and E, which upon refraction are incident on the "inner" groove face element 26 are reflected thereby as in the embodiment of Figures 1 and 2, although here the angle of reflection differs. The inclined "outer" facets in the upper side wall of the grooves make it possible favourably to "tune" the distribution of the reflected light . For example it will be appreciated that light from high in the sky generally falls further "outboard" (ie: towards the left as viewed in Figure 3) on the facets 26, 27 than the light arriving lower elevations. It is possible therefore to optimise the angle of the "outer" facet 27 to direct these higher elevation rays into the room at a desired angle.

By contrast with the embodiment of Figures 1 and 2, however, some of the light incident on the incident surface between adjacent surface elements 17, that is light entering the grooves 16, will fall on the lower side wall 19 of the groove. After refraction some of the rays, exemplified by rays F and G in Figure 3, impinge on the triangular prism constituted by the two groove bottom walls 20, 21 and are reflected upon arrival at the lower groove bottom wall 22 back to the upper groove bottom wall 21 where they are again reflected as illustrated in Figure 3 .

Some of the light, however, as exemplified by light ray H does not impinge on the triangular prism even after refraction at the interfaces 19 and 27, and is refracted again, at the interfaces 19 and 26 of the next lower groove. Then, being deeper into the body 12 of the optical element when arriving at the prism constituting the bottom of the next lower groove it is reflected in a manner as described above.

In the embodiment of Figure 4, where again corresponding components as indicated with the same reference numerals as in the embodiment of Figure 1, the groove upper and lower side walls 18, 19 are both planar and both perpendicular to the incident surface elements 17. The behaviour of this embodiment differs from that of Figure 1 inasmuch as the light, exemplified by ray K, exiting the room through the exit surface 14 and travelling through the body 12 towards the incident surface 17 is reflected five times before being returned to the room. Light from outside (the left of Figure 4) incident on those areas of the exit surface 14 in register with the elementary surfaces 17 will pass straight through, as exemplified by the light ray L.

The embodiment of Figure 5 is quite different from those of Figures 1 to 4 but operates on the same basic principle. It provides an interface for sweeping up and reflecting incident light arriving between elementary surfaces 17, that is light which enters the grooves 16. In order to achieve this the side walls of the upper walls of the grooves 16 are formed, like the embodiment of Figure 3, as two elementary side wall facets comprising an inner upper groove side wall facet 26 and an outer upper groove side wall facet 27. The groove lower wall is composed of three facets inclined at shallow angles to one another and comprising an inner facet 28, an intermediate facet 29 and an outer facet 30. The effect of this is to orientate the reflecting interfaces appropriately to divert incoming light rays as exemplified by rays M, N, 0, P of Figure 5.

Figure 6 illustrates a further alternative embodiment in which, in place of the elementary faces or lands 17 of the incident surface 13 the bottom of each groove is formed as a flat elementary face 32. The groove side walls comprise a flat, inclined upwardly facing lower side wall 19 and a composite downwardly facing, upper side wall comprising inner upper wall facets 31, intermediate upper wall facets 32 and outer upper wall facets 33. The side walls or side wall facets defining adjacent grooves meet at an intersection line 134 such that adjacent grooves are effectively contiguous. Typical light ray paths for one angle of incidence are illustrated. Figures 7 and 8 illustrates an embodiment in which there are both flat incident surface facets 17 and flat groove bottom walls 32. The upwardly facing groove bottom wall 19 is flat and perpendicular to the incident face 17, and the downwardly facing groove upper wall is composed of three facets 31, 32, 33 like the embodiment of Figure 6. In this embodiment light at an angle above the horizontal less than a certain threshold value and incident on either the flat surface elements 17 or the flat groove bottoms 32 is transmitted through substantially undeviated to allow the external environment to be viewed from the inside.

On the other hand, light arriving from above this threshold angle and entering a groove 16 is refracted at the face 19 and then reflected at one of the facets 31,

32, 33 to be directed through the exit face at a slight rising inclination. Light arriving in any given direction at the interface defined by the upper groove wall facets 31, 32, 33 is reflected more steeply from the facet 31 nearer the groove bottom than from the facet

33 nearer the mouth of the groove so that for a given angle of incidence some of the light leaving the exit face 14 is directed in a stepper direction than the remainder of the light arriving at this angle of incidence .

This provision of several facets also serves to ensure that incident rays from a relatively wide range of high angles above the horizontal is transmitted through the element to exit within a relatively narrow range of relatively low angles above the horizontal. This is illustrated in Figure 8 in which three incident light rays Q, R and S at successively smaller angles of incidence are shown. As will be seen, because of the relative inclination of the facets 31, 32 and 33 the emerging light rays are all generally parallel to one another and all inclined upwardly at a shallow angle which encourages good penetration to the back of the room furthest from the opening.

All of the optical elements described herein may be self- supporting or may be formed as films to be faced on to a transparent support such as a window pane. Such support is preferably provided on the incident face, namely to the left of the element as shown in the drawings, and this may be the outer layer of a double glazing cell. This has the advantage of isolating the grooves, which may be very fine features, from dust and other atmospheric contaminants. The dimensions of the grooves may typically be from to in width and from to in depth. Although described as a unitary element it will be understood that the invention may be put into practice as a composite element made up from a plurality of parts, as long as the faces and interfaces have or provide the same relationships.

Claims

1. An optical element comprising a transparent body having two substantially parallel major faces one of which is interrupted with a plurality of cavities defining a plurality of interfaces at which light incident thereon over a certain range of angles is reflected by total internal reflection, characterised in that at least some of the light incident on the said body is substantially undeviated in its transmission through the body, in that the said one face of the element in which the cavities are formed is intended in use to face a source of light, and in that the width of the cavities is such that at least a substantial proportion of the light incident on the said one face enters the said cavities.
2. An optical element as claimed in Claim 1, in which the cavities are formed as elongate grooves in the said one face of the body.
3. An optical element as claimed in Claim 2, in which the elongate grooves constituting the said cavities are defined by at least two side walls and the maximum groove width, namely the maximum separation between the groove walls is not less than the separation between adjacent grooves.
4. An optical element as claimed in any of Claims 1 to 3, in which the surrounding medium is air.
5. An optical component as claimed in any preceding claim, in which the said body is a unitary element of flexible material adapted to be supported on a face of a substantially planar transparent support element.
6. An optical element as claimed in any of Claims 1 to 4 , in which the said body is composed of a plurality of juxtaposed or connected elementary parts.
7. An optical element as claimed in any preceding claim, in which at least one of the walls of at least some of the cavities is formed as a curved surface.
8. An optical element as claimed in any preceding claim, in which at least one of the walls of at least some of the cavities is composed of at least two substantially planar wall elements or facets inclined at a non-zero angle to one another.
9. An optical element as claimed in any of Claims 2 to 8, in which at least some of the elongate grooves in the said one face of the body have a groove bottom constituted by the intersection of the groove side wall elements, or by the intersection of a groove side wall element with a groove side wall.
10. An optical element as claimed in any of Claims 2 to 8, in which at least some of the elongate grooves in the said body have a bottom wall defined by two surfaces inclined to one another at a reflex angle.
11. An optical element as claimed in Claim 10, in which the included angle at which the said two bottom wall surfaces meet is greater than the angle between the two groove walls or the wall surface elements or facets adjacent the groove bottom.
12. An optical element as claimed in any of Claims 2 to 8, in which at least some of the elongate grooves in the said one face of the body have a substantially flat bottom substantially parallel to the other said major face.
13. An optical element as claimed in Claim 12, in which adjacent grooves are contiguous.
14. An optical element as claimed in any of Claims 2 to
13 , in which the pitch of the grooves is of the same order of magnitude as the depth of the grooves .
15. An optical element as claimed in any of Claims 2 to
14, in which the depth of the grooves is of the order of, or less than 1 mm.
16. An optical element as claimed in any preceding claim, in which the depth of the cavities is in the region of half the thickness of the element between the major faces.
17. An optical element as claimed in any preceding claim, in which the shape of the cavities is such that light entering a cavity is refracted at the cavity side wall towards a next adjacent cavity and light thus arriving at the side wall of the said next adjacent cavity is reflected by total internal reflection.
18. An optical element as claimed in Claim 17, in which the side walls of the cavities are so formed as to define a plurality of side wall facets at each of which a proportion of the refracted light is deflected so as to be below the threshold angle for the next adjacent surface element in the path of the incident light.
19. An optical element as claimed in Claim 17 or Claim 18, in which the side wall facets of substantially parallel grooves in the said one face of the element extend generally horizontally when the element is in its intended position of use, and those facets defining generally downwardly facing surfaces of the grooves are inclined to one another at shallow angles such that each said downwardly facing groove-defining surface is downwardly convex.
20. A glazing assembly for an opening in a body, such as a building, a vehicle, a vessel or an aircraft, comprising a substantially rigid panel of transparent material having an optical element as claimed in any preceding claim affixed thereto by a substantially transparent cement or bonding agent .
21. A glazing assembly according to Claim 20, in which the said one face of the optical element is orientated towards the said support panel.
22. A glazing assembly according to Claim 20, in which the said one face of the optical element is oriented away from the said support panel.
23. A glazing assembly according to Claim 22, in which the said support panel is one of two substantially parallel panels of a double glazing cell and the said one face of the optical element faces towards the other of the said panel of the cell.
PCT/GB1997/000517 1996-02-21 1997-02-21 A light-diverting optical element WO1997031276A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB9603639.7 1996-02-21
GBGB9603639.7A GB9603639D0 (en) 1996-02-21 1996-02-21 A light-diverting optical component

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU18880/97A AU1888097A (en) 1996-02-21 1997-02-21 A light-diverting optical element
GB9817985A GB2328239B (en) 1996-02-21 1997-02-21 A light-diverting optical element

Publications (1)

Publication Number Publication Date
WO1997031276A1 true WO1997031276A1 (en) 1997-08-28

Family

ID=10789135

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1997/000517 WO1997031276A1 (en) 1996-02-21 1997-02-21 A light-diverting optical element

Country Status (3)

Country Link
AU (1) AU1888097A (en)
GB (1) GB9603639D0 (en)
WO (1) WO1997031276A1 (en)

Cited By (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2341632A (en) * 1998-09-18 2000-03-22 Milner Peter J Optical component for redirecting light entering a building comprises two optically transparent bodies defining voids
WO2000016132A1 (en) * 1998-09-15 2000-03-23 Peter Milner Prismatic array for rear view mirror
WO2000042451A1 (en) * 1999-01-14 2000-07-20 Minnesota Mining And Manufacturing Company Optical sheets suitable for spreading light
WO2002023258A2 (en) * 2000-09-14 2002-03-21 3M Innovative Properties Company Optical sheets suitable for spreading light
US6452734B1 (en) 2001-11-30 2002-09-17 The University Of British Columbia Composite electrophoretically-switchable retro-reflective image display
US6574025B2 (en) 1997-09-04 2003-06-03 The University Of British Columbia Optical switching by controllable frustration of total internal reflection
WO2004099823A2 (en) * 2003-05-02 2004-11-18 Reflexite Corporation Light-redirecting optical structures
US6865011B2 (en) 2002-07-30 2005-03-08 The University Of British Columbia Self-stabilized electrophoretically frustrated total internal reflection display
US6885496B2 (en) 2002-03-04 2005-04-26 The University Of British Columbia Wide viewing angle reflective display
US7164536B2 (en) 2005-03-16 2007-01-16 The University Of British Columbia Optically coupled toroidal lens:hemi-bead brightness enhancer for total internal reflection modulated image displays
JP2012255951A (en) * 2011-06-10 2012-12-27 Dainippon Printing Co Ltd Natural lighting sheet
US20130181143A1 (en) * 2011-07-14 2013-07-18 Howard Hughes Medical Institute Microscopy with adaptive optics
WO2013153216A1 (en) * 2012-04-13 2013-10-17 Airbus Operations Gmbh Daylight input in aircraft
US8730573B2 (en) 2009-07-09 2014-05-20 Howard Hughes Medical Institute Adaptive optics microscopy with phase control of beamlets of a light beam
JP2014126713A (en) * 2012-12-26 2014-07-07 Dainippon Printing Co Ltd Lighting sheet, lighting device and building
JP2014126708A (en) * 2012-12-26 2014-07-07 Dainippon Printing Co Ltd Lighting sheet, lighting device and building
WO2014196596A1 (en) * 2013-06-07 2014-12-11 シャープ株式会社 Lighting film, window glass, roll screen, and lighting louver
EP2418692A3 (en) * 2010-08-09 2014-12-24 Palo Alto Research Center Incorporated Stationary sunlight redirecting element and system
WO2015085060A1 (en) * 2013-12-06 2015-06-11 Dow Global Technologies Llc Daylighting film with glare control
WO2015098940A1 (en) * 2013-12-25 2015-07-02 シャープ株式会社 Daylight-admitting member, window glass, shade, and daylight-admitting louver
JP2015135503A (en) * 2015-02-16 2015-07-27 大日本印刷株式会社 Lighting sheet, lighting device, and building
WO2015119071A1 (en) * 2014-02-04 2015-08-13 シャープ株式会社 Daylighting member, daylighting device, and method for installing daylighting member
JP2015161811A (en) * 2014-02-27 2015-09-07 大日本印刷株式会社 Light control member, roll screen, daylighting sheet, and window with light control layer
JP2016014899A (en) * 2015-10-16 2016-01-28 大日本印刷株式会社 Natural lighting sheet, window glass and roll screen
WO2016028766A1 (en) * 2014-08-19 2016-02-25 SerraLux Inc. High efficiency daylighting structure
JP2016033673A (en) * 2015-10-16 2016-03-10 大日本印刷株式会社 Natural lighting sheet, window glass, and roll screen
JP2016042186A (en) * 2015-10-16 2016-03-31 大日本印刷株式会社 Natural lighting sheet, window glass, and roll screen
JP2016065999A (en) * 2014-09-25 2016-04-28 シャープ株式会社 Transmission type screen and rear projection type display device
US9366403B2 (en) 2013-03-21 2016-06-14 Dai Nippon Printing Co., Ltd. Daylighting sheet, daylighting panel, roll-up daylighting screen and method of manufacturing daylighting sheet
JP2016136263A (en) * 2016-02-18 2016-07-28 大日本印刷株式会社 Daylighting sheet, daylighting device and building
JP2016148851A (en) * 2016-02-18 2016-08-18 大日本印刷株式会社 Lighting sheet, lighting device, and building
JP2017021381A (en) * 2016-10-19 2017-01-26 大日本印刷株式会社 Daylighting sheet, daylighting device and building
WO2017018447A1 (en) * 2015-07-28 2017-02-02 シャープ株式会社 Natural-lighting film, die for forming natural-lighting film, and manufacturing method for natural-lighting film
WO2017022792A1 (en) * 2015-08-04 2017-02-09 シャープ株式会社 Daylighting member, daylighting device, and installation method for daylighting member
JPWO2016084752A1 (en) * 2014-11-25 2017-04-27 大日本印刷株式会社 Lighting sheet and lighting laminate
JPWO2016195054A1 (en) * 2015-05-29 2017-07-13 大日本印刷株式会社 Lighting member
US9817161B2 (en) 2014-10-20 2017-11-14 3M Innovative Properties Company Sun-facing light redirecting films with reduced glare
EP2513684A4 (en) * 2009-12-17 2018-01-17 3M Innovative Properties Company Light redirecting film laminate
US9910192B2 (en) 2014-10-20 2018-03-06 3M Innovative Properties Company Room-facing light redirecting films with reduced glare
US10161585B2 (en) 2015-05-21 2018-12-25 SerraLux Inc. Louver assembly

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4411493A (en) * 1981-10-05 1983-10-25 Miller Jack V Seasonal control skylight glazing panel with passive solar energy switching
US4557565A (en) * 1981-10-09 1985-12-10 Unisearch Limited Beam sunlighting device for building interiors
US4989952A (en) * 1987-11-06 1991-02-05 Edmonds Ian R Transparent light deflecting panel for daylighting rooms
WO1991003682A1 (en) * 1989-09-08 1991-03-21 Queensland University Of Technology Illuminating apparatus
WO1994025792A2 (en) * 1993-05-04 1994-11-10 Milner Peter J An optical component suitable for use in glazing

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4411493A (en) * 1981-10-05 1983-10-25 Miller Jack V Seasonal control skylight glazing panel with passive solar energy switching
US4557565A (en) * 1981-10-09 1985-12-10 Unisearch Limited Beam sunlighting device for building interiors
US4989952A (en) * 1987-11-06 1991-02-05 Edmonds Ian R Transparent light deflecting panel for daylighting rooms
WO1991003682A1 (en) * 1989-09-08 1991-03-21 Queensland University Of Technology Illuminating apparatus
WO1994025792A2 (en) * 1993-05-04 1994-11-10 Milner Peter J An optical component suitable for use in glazing

Cited By (63)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6574025B2 (en) 1997-09-04 2003-06-03 The University Of British Columbia Optical switching by controllable frustration of total internal reflection
WO2000016132A1 (en) * 1998-09-15 2000-03-23 Peter Milner Prismatic array for rear view mirror
GB2341632B (en) * 1998-09-18 2003-04-23 Milner Peter J Optical components for daylighting & other purposes
GB2341632A (en) * 1998-09-18 2000-03-22 Milner Peter J Optical component for redirecting light entering a building comprises two optically transparent bodies defining voids
US6456437B1 (en) 1999-01-14 2002-09-24 3M Innovative Properties Company Optical sheets suitable for spreading light
WO2000042451A1 (en) * 1999-01-14 2000-07-20 Minnesota Mining And Manufacturing Company Optical sheets suitable for spreading light
WO2002023258A3 (en) * 2000-09-14 2003-02-06 3M Innovative Properties Co Optical sheets suitable for spreading light
WO2002023258A2 (en) * 2000-09-14 2002-03-21 3M Innovative Properties Company Optical sheets suitable for spreading light
US6452734B1 (en) 2001-11-30 2002-09-17 The University Of British Columbia Composite electrophoretically-switchable retro-reflective image display
US6885496B2 (en) 2002-03-04 2005-04-26 The University Of British Columbia Wide viewing angle reflective display
US6891658B2 (en) 2002-03-04 2005-05-10 The University Of British Columbia Wide viewing angle reflective display
US6865011B2 (en) 2002-07-30 2005-03-08 The University Of British Columbia Self-stabilized electrophoretically frustrated total internal reflection display
WO2004099823A2 (en) * 2003-05-02 2004-11-18 Reflexite Corporation Light-redirecting optical structures
WO2004099823A3 (en) * 2003-05-02 2005-11-24 Robert B Nilsen Light-redirecting optical structures
US7330315B2 (en) 2003-05-02 2008-02-12 Reflexite Corporation Light-redirecting optical structures
US7164536B2 (en) 2005-03-16 2007-01-16 The University Of British Columbia Optically coupled toroidal lens:hemi-bead brightness enhancer for total internal reflection modulated image displays
US8730573B2 (en) 2009-07-09 2014-05-20 Howard Hughes Medical Institute Adaptive optics microscopy with phase control of beamlets of a light beam
EP2513684A4 (en) * 2009-12-17 2018-01-17 3M Innovative Properties Company Light redirecting film laminate
EP2418692A3 (en) * 2010-08-09 2014-12-24 Palo Alto Research Center Incorporated Stationary sunlight redirecting element and system
JP2012255951A (en) * 2011-06-10 2012-12-27 Dainippon Printing Co Ltd Natural lighting sheet
US8629413B2 (en) * 2011-07-14 2014-01-14 Howard Hughes Medical Institute Microscopy with adaptive optics
US20130181143A1 (en) * 2011-07-14 2013-07-18 Howard Hughes Medical Institute Microscopy with adaptive optics
WO2013153216A1 (en) * 2012-04-13 2013-10-17 Airbus Operations Gmbh Daylight input in aircraft
JP2014126713A (en) * 2012-12-26 2014-07-07 Dainippon Printing Co Ltd Lighting sheet, lighting device and building
JP2014126708A (en) * 2012-12-26 2014-07-07 Dainippon Printing Co Ltd Lighting sheet, lighting device and building
US9366403B2 (en) 2013-03-21 2016-06-14 Dai Nippon Printing Co., Ltd. Daylighting sheet, daylighting panel, roll-up daylighting screen and method of manufacturing daylighting sheet
US10100992B2 (en) 2013-03-21 2018-10-16 Dai Nippon Printing Co., Ltd. Daylighting sheet, daylighting panel and roll-up daylighting screen
US9708847B2 (en) 2013-03-21 2017-07-18 Dai Nippon Printing Co., Ltd. Daylighting sheet, daylighting panel and roll-up daylighting screen
US9803818B2 (en) 2013-06-07 2017-10-31 Sharp Kabushiki Kaisha Lighting film, window glass, roll screen, and lighting louver
JPWO2014196596A1 (en) * 2013-06-07 2017-02-23 シャープ株式会社 Lighting film, window glass, blinds and lighting louver
WO2014196596A1 (en) * 2013-06-07 2014-12-11 シャープ株式会社 Lighting film, window glass, roll screen, and lighting louver
CN105308483A (en) * 2013-06-07 2016-02-03 夏普株式会社 Lighting film, window glass, roll screen, and lighting louver
WO2015085060A1 (en) * 2013-12-06 2015-06-11 Dow Global Technologies Llc Daylighting film with glare control
JPWO2015098940A1 (en) * 2013-12-25 2017-03-23 シャープ株式会社 Lighting members, window glass, blinds, lighting louver
WO2015098940A1 (en) * 2013-12-25 2015-07-02 シャープ株式会社 Daylight-admitting member, window glass, shade, and daylight-admitting louver
CN105960602A (en) * 2014-02-04 2016-09-21 夏普株式会社 Daylighting member, daylighting device, and method for installing daylighting member
JPWO2015119071A1 (en) * 2014-02-04 2017-03-23 シャープ株式会社 Installation of lighting members, lighting apparatus, and lighting member
RU2660919C1 (en) * 2014-02-04 2018-07-11 Шарп Кабусики Кайся Lighting element, a lighting device and a method for mounting the lighting device
US9970613B2 (en) 2014-02-04 2018-05-15 Sharp Kabushiki Kaisha Lighting member, lighting device, and method for installing lighting member
WO2015119071A1 (en) * 2014-02-04 2015-08-13 シャープ株式会社 Daylighting member, daylighting device, and method for installing daylighting member
CN105960602B (en) * 2014-02-04 2018-07-13 夏普株式会社 The method of setting the lighting means of the lighting device and the lighting member
EP3104200A4 (en) * 2014-02-04 2017-02-22 Sharp Kabushiki Kaisha Daylighting member, daylighting device, and method for installing daylighting member
JP2015161811A (en) * 2014-02-27 2015-09-07 大日本印刷株式会社 Light control member, roll screen, daylighting sheet, and window with light control layer
WO2016028766A1 (en) * 2014-08-19 2016-02-25 SerraLux Inc. High efficiency daylighting structure
US9803817B2 (en) 2014-08-19 2017-10-31 SerraLux Inc. High efficiency daylighting structure
JP2016065999A (en) * 2014-09-25 2016-04-28 シャープ株式会社 Transmission type screen and rear projection type display device
EP3210057A4 (en) * 2014-10-20 2018-05-23 3M Innovative Properties Company Sun-facing light redirecting films with reduced glare
US10151860B2 (en) 2014-10-20 2018-12-11 3M Innovative Properties Company Sun-facing light redirecting films with reduced glare
US9817161B2 (en) 2014-10-20 2017-11-14 3M Innovative Properties Company Sun-facing light redirecting films with reduced glare
US9910192B2 (en) 2014-10-20 2018-03-06 3M Innovative Properties Company Room-facing light redirecting films with reduced glare
JPWO2016084752A1 (en) * 2014-11-25 2017-04-27 大日本印刷株式会社 Lighting sheet and lighting laminate
JP2015135503A (en) * 2015-02-16 2015-07-27 大日本印刷株式会社 Lighting sheet, lighting device, and building
US10161585B2 (en) 2015-05-21 2018-12-25 SerraLux Inc. Louver assembly
JPWO2016195054A1 (en) * 2015-05-29 2017-07-13 大日本印刷株式会社 Lighting member
WO2017018447A1 (en) * 2015-07-28 2017-02-02 シャープ株式会社 Natural-lighting film, die for forming natural-lighting film, and manufacturing method for natural-lighting film
EP3333476A4 (en) * 2015-08-04 2019-03-20 Sharp Kk Daylighting member, daylighting device, and installation method for daylighting member
WO2017022792A1 (en) * 2015-08-04 2017-02-09 シャープ株式会社 Daylighting member, daylighting device, and installation method for daylighting member
JP2016014899A (en) * 2015-10-16 2016-01-28 大日本印刷株式会社 Natural lighting sheet, window glass and roll screen
JP2016042186A (en) * 2015-10-16 2016-03-31 大日本印刷株式会社 Natural lighting sheet, window glass, and roll screen
JP2016033673A (en) * 2015-10-16 2016-03-10 大日本印刷株式会社 Natural lighting sheet, window glass, and roll screen
JP2016136263A (en) * 2016-02-18 2016-07-28 大日本印刷株式会社 Daylighting sheet, daylighting device and building
JP2016148851A (en) * 2016-02-18 2016-08-18 大日本印刷株式会社 Lighting sheet, lighting device, and building
JP2017021381A (en) * 2016-10-19 2017-01-26 大日本印刷株式会社 Daylighting sheet, daylighting device and building

Also Published As

Publication number Publication date
GB9603639D0 (en) 1996-04-17
AU1888097A (en) 1997-09-10

Similar Documents

Publication Publication Date Title
EP0293182B1 (en) Light fixture providing normalized output
US6895164B2 (en) Hollow wedge shaped light guide
CN1148605C (en) Lighting device
DE69628766T2 (en) Easily recognizable marking system
AU752774B2 (en) Optical film
JP4011287B2 (en) Light control sheet, the surface light source device and liquid crystal display
US5735590A (en) Backlighting device with a transparent sheet having straight ridges
CA2376387C (en) Lighting apparatus and liquid crystal display
AU614022B2 (en) Internally illuminated retroreflective sign
US4765701A (en) Illuminator optical fiber rod
EP1092112B1 (en) Structure for achieving a linear light source geometry
US20040136196A1 (en) Vehicle lamp
EP1445629A1 (en) A light guide panel with slant light guiding parts
US4642736A (en) Light diffuser
US20040161222A1 (en) Optical waveguide, area light source device and liquid crystal display device
US20130033873A1 (en) Optical device and illuminating device
US7226182B2 (en) Lighting block using solar cells
EP0271956B1 (en) A liquid crystal display illumination system
US6305811B1 (en) Illumination system having an array of linear prisms
US5608550A (en) Front-lit liquid crystal display having brightness enhancing film with microridges which directs light through the display to a reflector
US4509825A (en) Directing and controlling the distribution of radiant energy
CA2343281C (en) Illumination system using edge-illuminated hollow waveguide and lenticular optical structures
CA2372584C (en) Aircraft lighting unit using led's
US3936157A (en) High efficiency light transmitting window panel
US20040137189A1 (en) Optical device and light guide system comprising it

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE HU IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TR TT UA UG US UZ VN AM AZ BY KG KZ MD RU TJ TM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): KE LS MW SD SZ UG AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
ENP Entry into the national phase in:

Ref country code: GB

Ref document number: 9817985

Kind code of ref document: A

Format of ref document f/p: F

WWE Wipo information: entry into national phase

Ref document number: 9817985.6

Country of ref document: GB

NENP Non-entry into the national phase in:

Ref country code: JP

Ref document number: 97529919

Format of ref document f/p: F

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase