CH686050A5 - A device for automatically controlling the incident light into a room. - Google Patents

Description

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description

The invention relates to a device for automatic control of the incidence of light in a room according to the preamble of claim 1.

For optimal use of sunlight in residential or business premises, it is necessary to direct the incident sunlight and / or convert it into another form of energy. So-called blinds have been used as simple yet effective light directing elements for decades. These are mostly adjustable, horizontally arranged papers made of wood, plastic or light metal, which are operated by means of a cord and more or less block the light. However, vertically arranged slats are also known, the setting angle of which can be changed such that a more or less large shading of an interior space occurs. The blinds with horizontal slats are better suited for shading, while the blinds with vertical slats better shield the sun's rays when the sun is low. These known blinds with vertical or horizontal slats serve primarily as sun protection, i.e. they absorb at least part of the incident solar energy. They are not suitable for sensible use of the sparse sunlight in winter. In addition, they can only be set inaccurately and therefore do not allow precise light control. In addition, the well-known blinds with horizontal slats cannot meet the modern requirements for glare-free workstations at VDU workstations. Too high brightness contrasts between the screen and the screen background, due to reflection on the screen surface and due to excessive incidence of external light on the screen can cause unpleasant glare to the users of screens. If blinds with vertical slats are used to reduce these negative phenomena, the interior is largely darkened, which in turn leads to an increased need for artificial light and thus to energy wastage, especially at a time when there is sufficient outside brightness around the interior natural way to brighten.

In addition to these blinds, which have been known for a long time, there have also been passive light control systems in which the light control systems are rigidly arranged and have a special surface design (EP-C 0 029 442; H. Köster: New energy management in the facade, DAB 3/1990 , Pp. 399 to 402; H. Köster: Use of solar energy and daylight in residential and administrative buildings - new daylight directing technology in windows and facades, DAB 7/1991, pp. 1101 to 1105; DE-C-3 122 164; WO 90 / 10176) The light directing profiles have a profile diameter of approx. 1.5 cm to 3 cm and usually extend across the entire width of a window. These light control systems are often embedded between two glass panes; however, you can also without

Glass panes can be arranged on a house facade or on a roof. With these light control systems, i.a. achieved that a room is shaded as much as possible in summer and optimally illuminated in winter. However, at flat angles of incidence, the light is deflected only by a single reflection on the ceiling in the immediate vicinity of the window, and it is only reflected in the depth of the interior by two reflections as the angle of the sun increases. If the angle of incidence continues to increase, some radiation components are also directed to the floor of the interior by two reflections, which can lead to direct glare from an observer looking at the window. It is therefore not possible to avoid glare at all angles of incidence of sunlight. However, glare, regardless of whether it is physiological or psychological, is extremely unpleasant, especially when the source of glare is to the side or below the line of sight (H. Schober, DAS SEHEN, Volume II, Leipzig 1964, pp. 72 to 107).

Various calculations have already been carried out on the relationship between lamella size and lamella space, but they do not provide any information about how this relationship affects the glare (K. Matsuura: General calculation method of illuminance from a vertical louver blind system, 1983, International daylight conference, Phoenix, Arizona, USA, February 16, 1983, pp. 213-218; S. Rheault, L. Bilgen: Heat transfer analysis in an automated venetian blind window system, Journal of Solar Engineering, February 1989, p. 89-95).

Furthermore, these known calculation methods are not suitable for systems in which complex light-guiding profiles are used instead of simple slats. Novel “ray tracing programs” make it possible to simulate the course of light rays that are deflected by complex optical systems, but these programs assume ideal light rays and do not take into account that direct sunlight is not diverging, but parallel. The divergence of direct solar radiation is based on the fact that the sun is not, as is usually assumed, a point-shaped light source in the infinite, but because of its spherical shape acts like an area lamp. The diverging light radiation of a sphere the size of the sun creates umbra and penumbra zones even at a great distance. In the penumbra there is a constant transition from brightness to darkness. While there is only a clear shadow contour, the umbra, directly behind a shadow-casting body, the penumbra zone increases with greater distance from the shadow-casting object, while the umbra becomes increasingly blurred. This effect is known from solar and lunar eclipses, but has not yet been used in the calculation of light directing or shading systems.

In the sunlight is the umbra of a sphere

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about 108 times as long as the ball diameter, which follows from the relationship shadow length / ball diameter = sun distance / sun diameter (see Bergmann, Schäfer: Textbook of Experimental Physics, Volume III Optics, 7th edition, 1978, p. 4/5). The relationship, which is quite complicated even with a sphere, becomes even more confusing in the case of slat-like sun protection in that the slats extend over a large distance and, if appropriate, reflect and / or deflect light as reflecting elements. Another effect that only occurs with light gaps in the order of the light wavelengths is light diffraction. In the case of diffraction or diffraction, the light deviates from the geometrical-optical beam path, with part of the wave energy reaching the shadow area. In the macroscopic range of blinds, this effect can mostly be neglected. On the other hand, the fact that the angle of the sun in relation to the slats of a venetian blind changes constantly during the day and depending on the season cannot be neglected.

The sun is an oscillating light source that only occupies the same position twice a year. Since the direction of the incidence of light and the angle of the sun constantly change, it is a major problem to find an ideal location for a screen workstation in the floor plan.

The glare problem is not only limited to glare in an interior, which is illuminated by a blind or light control system, but also occurs outdoors when the slats or light control profiles are mirrored. If, for example, a window is provided with an at least partially mirrored light directing system that reflects light back, the back reflected light can lead to glare in opposite houses or in traffic. If such a light control system is used as a roof element, glare to air traffic is not excluded.

The invention is therefore based on the object of designing a device for automatically controlling the incidence of light in such a way that glare is considerably reduced or even eliminated, both in an interior illuminated by the device and in an exterior from which a light source shines on the device becomes.

This object is achieved according to the features of patent claim 1.

The advantage achieved by the invention is in particular that the light entering an interior space through a light control system is evened out at a short distance from the system, i.e. it no longer casts stripe-shaped shadows on the floor, ceiling or walls. This guarantees freedom from glare in the interior, which is particularly important for VDU workstations. In addition, there is also glare outside, i.e. in neighboring houses or on the street is avoided because the reflected light on a house facade is reflected very steeply down to the floor level. Furthermore, the miniaturization of the light-directing profiles results in improved transparency, which is a major advantage when using the light-directing profiles as window elements. In addition to the optical advantages that result from the special construction of the device according to the invention, this device also enables advantageous production, e.g. made of aluminium. Due to the miniaturization of the light-directing profiles, they can be easily embedded in acrylic, making it easy to handle light-directing plates. Furthermore, when a device according to the invention is installed in an insulating glass unit, there is a greater distance between the panes and the light-guiding profiles, which makes it possible to provide the space between the panes with a noble gas filling, which brings about greater thermal insulation. If the insulating glass panes bulge in winter due to the cooling of the gas contained in the space between the panes, there is no contact between the light-guiding profiles and panes, so that neither metal oxide coatings that can be applied to the inside of the panes are scratched, nor do heat-conducting contacts occur between the inner pane and the outer pane through the light-guiding system .

Embodiments of the invention are shown in the drawing and are described in more detail below. Show it:

Figure 1 is a schematic representation of two slats of a light control system, which are illuminated by a surface radiator.

2 shows a light control system with a plurality of slats arranged one above the other with quasi-parallel beams, the beams of which diverge within the bundle;

3 shows the light-directing profiles according to FIG. 1, but together with two glass panes, in the space between which the light-directing profiles lie;

Fig. 4 is a schematic representation for light directing profiles for installation in the window area;

5 shows a further schematic illustration for light directing profiles for installation in the skylight area;

6 shows a light control system embedded in plastic;

7 shows two light-guiding systems arranged parallel to one another in the air gap of an insulating glazing;

Fig. 8 shows a device according to Fig. 3, which is inclined to the horizontal.

1 shows a basic arrangement which illustrates how the sun's rays are guided through a light-guiding system. The sun is symbolized here by a surface radiator 1, which illuminates two light directing profiles 2, 3 of a light directing system. Behind these light-directing profiles 2, 3 is the room 4 to be illuminated. It goes without saying that the light-directing system generally has more than just two light-directing profiles 2, 3 arranged one above the other and that the light5

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Steering profiles can be arranged between two glass panes, plastic panes or flexible plastic films. Several points 5 to 10 are marked on the surface radiator 1, which represent all points of the radiating surface. From these points 5 to 10 light rays emanate in all directions to the right of the surface radiator 1, which - since diffraction phenomena are not to be considered - spread in a straight line. A few of these infinite light rays are shown in FIG. 1 in order to make the principle of light control and shadow formation clear. For example, point 5 has four different light beams 11 to 13 and 15, of which the light beam 11 affects the upper edge 17 of the light guide profile 2. A second light beam 12 affects a second edge 18 of the same light guide profile 2, while a third light beam 13 affects an upper edge 19 of the lower light guide profile 3 and a fourth light beam 15 affects a second edge 24 of the lower light guide profile 3. All three rays 11 to 13 emanating from point 5 reach space 4 directly.

The same considerations that apply to the rays emanating from point 5 also apply correspondingly to the rays emanating from points 6 to 10. From this it can already be seen that a mathematical description of the shading process is very complex. All rays entering directly into space 4 form a bundle 25, which tapers from the surface radiator 1 in the direction of the opaque light-directing profiles 2, 3, in order then to diverge again in space 4. This bundle is delimited by beams 12 and 26, beam 26 starting from point 10. The direct rays of the bundle 25 are superimposed on the rays entering the room due to deflection on the mirrored surface 21 of a light directing profile 3, but are not shown. The actual lighting conditions in room 4 are therefore hardly accessible to an exact mathematical description. Even if the surfaces 21, 22 of the light-directing profiles 2, 3, on which reflections take place, could be described mathematically, it would still have to be taken into account in a description that applies to practice that the sun changes its position continuously, so that in the case of a “conformal image” the surface radiator 1 would also have to be moved. If the surface emitter 1 moves upwards, it can be seen that fewer and fewer light rays are entering the room 4 and more and more are being reflected to the outside. This means that the light is mainly reflected in the summer when the sun is high, while in the winter when the sun is low it is mainly let through to room 4. If the surface radiator 1 assumes the position denoted by 1 'and shown in dashed lines, no direct light enters the room 4 at all, because the lower edge of the surface radiator V lies on the straight line formed by the corner points 19 and 28. Only diffuse light can thus pass through the opening between the two light beam profiles 2, 3.

From the illustration in FIG. 1 it can be seen that in summer in the morning, when the sun is already shining strongly, but is still low, a considerable proportion of light can enter the room 4 through the opening between the light-guiding profiles 2, 3. If the distance between the light-directing profiles 2, 3 is large and, in particular, the light-directing profiles 2, 3 themselves are large, the bundles entering the space 4, of which only the bundle 29 is shown, can produce glare effects or can be formed on the walls, so that bright streaks appear on the walls. Those rays that enter the room 4 via successive reflections on the surfaces 21, 22 also contribute to this effect.

Since the bundle of rays 29 opens and the rays reflected on the surface 22 likewise do not run parallel to the normal 16, overlaps of light rays occur in the space, which cause spots with greater and lesser brightness. The smaller the profiles, the greater the overlaps. However, the greater the overlap, the less the streak and glare effect. The view through a window that contains the light control system is also improved by smaller grids. If wide light directing profiles in height e.g. halved and brought into new equidistant arrangements, the overall brightness that shines through a window does not change because the light-shielding surface has remained the same. However, the locking has been refined so that more details can be seen outside. If the light directing profiles were to be reduced infinitely so that they would each have a distance corresponding to their strength, these light directing profiles would act like a gray filter with a transmission coefficient of 0.5, i.e. all details in the outside area would be recognizable, but only half as bright as without a light control system.

The opaque light-directing profiles 2, 3 cast - apart from the reflections that some rays pass through - an umbra, the length of which depends on the diameter of the light-directing profiles 2, 3. If the sun is perpendicular to the connecting line of points 28, 24, the umbra of the light directing profile 3 is approximately 108 times as long as the projection of the route 19-30. Assuming this distance of 3 cm, which is common in current systems, the length of the umbra is calculated to be 324 cm, i.e. At a distance of 324 cm from a light control system housed in a double glass pane, the light distribution is relatively inhomogeneous. With light directing profiles of e.g. 0.7 cm wide, the umbra is reduced considerably.

FIG. 2 schematically shows a light control system 34 which is arranged between two panes 35, 36. The outer space in which the sun is located, which takes over the function of the surface radiator 1 in FIG. 1, is designated by 37. In contrast to the illustration in FIG. 1, where the surface radiator 1 has a different geometric relationship to each light directing profile 2, 3, because the respective distances between the light directing profile 2

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or 3 and surface radiator 1, the relationship of the surface radiator sun in FIG. 2 to each light directing profile 38 to 55 is the same, because the distance between each light directing profile 38 to 55 and the sun is essentially the same. One can therefore for each one through the space between two light control profiles, e.g. 41 and 42, falling beams, e.g. 57, imagine your own sun as an output light source. This creates the umbra 80 to 85, which tapers down to a level 86. The umbra has disappeared behind level 86. Direct solar radiation 801 to 805 occurs between the light directing profiles, which causes bright stripes. These strips 801 to 805 mark the penumbra 806 to 817 between themselves and the umbra 80 to 85. These penumbras 806 to 817 begin to overlap behind the plane 86. New shadow zones 96 to 100 are formed. With a typical diameter of the light directing profile of approx. 2 cm, a relatively uniform illumination is only obtained at a distance of approx. 4 m. Since the desks of an office are usually less than 4 m from the window, striped images on the tables and on the walls are inevitable when the sun is low. These stripe patterns can be avoided by miniaturizing the light directing profiles with a width of approx. 0.7 mm.

While the creation of a glare-free interior has essentially been described so far, the following section deals with the creation of a glare-free exterior. The miniaturization of the light directing profiles is essential for glare-free interior. Although the profile shape also has an impact on the interior glare, it is of minor importance compared to miniaturization. It is different with outdoor glare, which is based primarily on the fact that sunlight is reflected back. The design of the profiles plays a significant role here.

This will be explained in more detail with reference to FIG. 3. In this figure, a section of an insulating glazing is shown as facade cladding, which is set up vertically to the surface of the earth, that is to say, for example, is arranged on house fronts or in window openings. Of a plurality of light directing profiles arranged in parallel one above the other, only the two light directing profiles 2, 3 are shown.

These light-directing profiles are arranged between two parallel alignments 300 and 301, which in turn run parallel to glass panes 110, 111. According to the invention, the arrangement shown in FIG. 3 has at least three characteristic features which, in their interaction, result in largely no glare in an interior and an exterior, the glass pane 110 facing the exterior and the glass pane 111 facing the interior.

The first characteristic variable is the distance a between the escapes. It is 10 mm or less. As a result, a miniaturization of the light guide profiles 2, 3 is prescribed, which is causal for a fine locking of the one entering the interior

Light is. However, this miniaturization is not sufficient in itself because corner point 17 of the light-guiding profile can be thought of as being drawn infinitely upwards, so that even a light-guiding profile could cause extensive shading of the interior. The distance b, which represents the maximum shading when the sun is moving, is therefore defined as the second variable. This distance b is defined by two parallel lines 302, 303, of which one line is defined by the corner points 28 and 19 of the light guide profiles 2, 3, while the other line 303 runs through the corner point 17 of the light guide profile 2.

The corner point 28 of the light guide profile 2 is the one that is directed towards the outside, while the corner point 17 of the same light guide profile 2 is a corner point directed towards the inside. The corner points 17 and 19 of the light directing profiles 2, 3 lie on the same alignment 301.

By setting the maximum shading b to 10 mm or less, the light directing profiles are also restricted in their vertical dimensions. In addition, the distance between the corner points 17, 28 and 19, 24 of a light-guiding profile 2 and 3 is determined indirectly. In theory, the corner point 18 of the light guide profile 2 could now be drawn to the corner point 19 of the light guide profile 3, so that complete shading of the interior could occur despite the miniaturization. However, this possibility is excluded by specifying an angle a of 15 ° or less. This angle a is spanned by two straight lines 304, 305, of which one straight line 304 is perpendicular to the alignments 300, 301, while the other goes through the two corner points 28, 18 and 24, 30 of the light guide profiles 2, 3. The angle of 15 ° refers to an arrangement of the alignments 300, 301 or disks 110, 111 perpendicular to the center of the earth, i.e. on a facade element.

If the alignments are inclined so that in extreme cases they are parallel to the tangent to the earth's surface, the angle a also changes. To ensure that the desired effects are retained even with a roof construction, the corner points 17, 19 and 28, 24 of the elements 2, 3 move along the lines 300, 301 when the panes 110, 111 e.g. be turned clockwise. Since the normals 304, 309 on the disks 110, 111 no longer run horizontally to the surface of the earth when the disks rotate, but are tilted by an angle β, if with e.g. the angle of a roof pitch is designated, a depends on ß. The simplified formula a = f (ß) + 15 ° (I) applies.

d. H. a is a function of ß plus 15 °.

Further details are explained in connection with FIG. 8.

The angle of 15 ° is only a very advantageous value; however, it can also fluctuate, preferably between 0 and 15 °. It

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However, inclinations of the straight line 35 below the horizontal 304 of approximately 10 ° are also entirely possible, so that the angle a is generally determined as follows:

a = f (ß) + (15 ° -x) (II)

where x is any angle - preferably between 0 ° and 25 ° - which is subtracted from 15 °. With x = 15 ° and with an arrangement according to FIG. 3, the straight line 305 would coincide with the horizontal 304.

In a particularly advantageous embodiment of the invention, the curvature of the outwardly directed section 32, 33 is determined by the fact that the curvature curve of this section 32, 33 lies completely below a straight line 308 which is at an angle 7 <30 ° with a straight line running parallel to the earth's surface includes and goes through the corner points 18, 30 of a light guide profile 2, 3. This rules out that the section 32, 33 can assume a special curvature that leads to glare despite the above-mentioned restrictions. The angle 7 can also depend on the angle of inclination β.

In a further advantageous embodiment of the invention, a radius r is defined, which defines a circumference 310 on which the most distant points 19, 24 of a light directing profile lie. This radius is less than or equal to 5 mm.

If one looks at the arrangement shown in FIG. 3, three solar radiation angles, namely a very flat one when the sun is just rising, a medium one at a sun at eye level and a high one at midday in the summer, one can see that the rays coming from below only indirectly , ie can enter the interior via reflections on the surfaces 32 and 21 and be blasted onto the ceiling there. The reflection into the outside space takes place obliquely downwards. In medium solar radiation, the light enters the interior through the opening, which is limited by points 18 and 19. Because of the short umbra, which is thrown through the profiles 2, 3, there is a light puddle at a short distance behind the escape 301, which is no longer perceived as dazzling. The radiation to the outside occurs steeply upwards via the mirrored surfaces 31 and 21, while it occurs steeply downwards via the mirrored surfaces 32 and 33. If the light control elements are used as roof facades with a roof pitch, they ensure that the light is reflected steeply downwards into the interior. This is particularly important for workplace lighting, so that e.g. Reflections on screens can be avoided.

When the sun is shining in from above, the light is emitted upwards through the surfaces 21, 31 in an arrangement according to FIG. 3 and reaches the interior through successive reflections on the surfaces 21 and 22 of the profiles 3 and 2, respectively. The light radiated directly from the surfaces 21, 31 into the interior reaches the ceiling, while the light directed by successive reflections on the surfaces 21 and 22 also reaches the ceiling.

4 again shows two light directing profiles 400, 401. In contrast to the light guide profiles 2, 3 described above, whose upper surfaces 21, 31 were curved in a parabolic manner, the upper surfaces of the light guide profiles 400, 401 consist of two parabolic individual surfaces 402, 403 and 404, 405. These individual surfaces have different axes and different focal points . This ensures that the light reflected in the interior 4 is not radiated to the ceiling, but first to the interior surfaces 406, 407 of the light-directing profiles 400, 401 and from there into the interior 4. The radiation 408, 409 can are thus essentially directed into the interior 4. The straight line 410, which includes a small angle 8 with the horizontal or horizontal 411, 409, designates the parabola axis to the surface 405. In contrast, the straight line 412, which includes a large angle cp with the horizontal 413, denotes a parabola axis to the surface 404. Die Positions at which the two different parabolic pieces 402, 403 and 404, 405 abut one another are denoted by 414 and 415, respectively.

By using two different parabolic pieces 402, 403 or 404, 405 it is achieved that good light distribution is achieved in high solar radiation as well as in low solar radiation and glare in the interior can thereby be avoided by primarily directing the light onto the underside 406 locked to the interior , 407 mirrored and from there deflected into the depth of the interior. A redirection from top to bottom is excluded. The first parabolic section 402 or 404 is to a certain extent responsible for the deflection in summer and thus for the high angles of incidence, while the second parabolic section 403, 405 is responsible for the deflection in winter and thus for the low angles of incidence. Accordingly, the tangents to the second parabola section 403, 405 have a greater steepness with respect to a horizontal straight line than the tangents to the first parabola section 402, 404. The straight lines 416, 417 or 418, 419 or 420, 421 or 422, 423 denote further incident light rays and their deflection.

5 shows a plurality of light-directing profiles arranged one above the other, which are constructed according to the principle shown in FIG. 4. In contrast to the light-directing profiles according to FIG. 4, however, the light-directing profiles according to FIG. 5 each have two para-bell-shaped sections 506, 507; 508, 509; 510, 511; 512, 513; 514, 515, which are staggered in the vertical direction, i.e. there is a further piece 516 to 520 between them. From the illustration in FIG. 5, in which the incident beams 521 to 524 of the different positions of the sun are shown, it can be seen that the light does not flood from top to bottom at any position of the sun.

With the in connection with FIGS. 1 to 3

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As already mentioned, the miniaturization of the light directing system described can achieve a very good homogeneity of the light radiated or directed into a room. If the miniaturized light control systems are then equipped with two different parabolic surfaces, as shown in FIGS. 4 and 5, the glare effect is additionally eliminated by the light being reflected very deeply into the interior via the interior sides of the profile undersides and thus distributed evenly in the interior becomes.

Miniaturization offers further possibilities, which are difficult to achieve with large light-guiding profiles.

Thus, as shown in FIG. 6, the light-directing profiles 601 to 606 forming a light-directing system 600 can be encased in a transparent plastic 607, e.g. Acrylic, embed and arrange as a plate-shaped element between two glass panes 608, 609 or use as an insulated element. If the plate-shaped element is glued to the two glass panes 608, 609, a laminated glass pane is created.

When the light-directing profiles 601 to 606 are poured into the plastic material 607, the surfaces of the light-directing profiles 601 to 606 must be designed somewhat differently than the light-directing profiles shown in the previous drawings, because the light refractive index of the acrylic glass must be taken into account.

Another arrangement of the miniaturized light control system is that it is between two normal heat-insulating panes of e.g. 16 mm distance can be provided twice.

In Fig. 7 a device is shown which contains two light control systems 701, 702, each of which has a plurality of light control profiles, e.g. 703, 704 or 705, 706. Both light control systems are arranged parallel to and between glass panes 707, 708. A special feature of the device shown in FIG. 7 is that the light control system 702 is rotated by 180 degrees with respect to the light control system 701. It would also be possible to cross the two systems orthogonally, so that e.g. in FIG. 7 it would not be possible to see the profile cross-sections of the system 702, but rather an entire light-guiding profile extending from the bottom to the top.

In a further embodiment of the invention, the profiles can be wrapped in foils. Here, the corner points 17, 19 and 28, 24 of the profiles 2, 3 (see FIG. 3) touch the inner walls of flexible plastic sheets, which to a certain extent take the place of the alignments 300, 301. By using two plastic films, the heat transfer coefficient of a four-pane glazing is achieved without having to put up with the glare effects of four-pane glazing. The foils are arched inward by vacuum effects between the corner points 17, 19 and 28, 24 such that reflections on the foil surfaces do not lead to glare.

In the description, the term “parabolic” is always understood to mean a curved concave surface; this surface can also be arc-shaped or curved in some other way.

FIG. 8 shows a device which essentially corresponds to the device according to FIG. 3, but which, in contrast to this, is not used for a facade but for a sloping roof. The device according to FIG. 3 is to a certain extent rotated clockwise. The angle through which the device of FIG. 8 is rotated relative to the device of FIG. 3 is called β. This angle β can be related to the vertical, which corresponds to the perpendicular to the center of the earth and is identical to the alignments 300, 301 in FIG. 3, or to the horizontal, which corresponds to a parallel to the tangent to the circumference of the earth. Since the angle a has already been referred to the straight line 304, which corresponds to the horizontal in FIG. 3, the angle β is also referred to the horizontal in the following. This horizontal is provided with the reference number 800 in FIG. 8. It can be seen from the illustration in FIG. 8 that the straight line 304, which represents the normal to the alignments 300, 301, no longer coincides with the horizontal.

By rotating the entire device clockwise, the normal 304 originally lying below the straight line 305 now passes above this straight line 305, i.e. the normal

304 related angle a becomes negative. With this twisting of the entire device, the positions of the corner points 24, 30, 19 of a profile within the space between the two alignments 300, 301 also change, to a certain extent they rotate counterclockwise. This relative counterclockwise rotation within the alignments 300, 301 also clearly meets the straight line

305 to. The angle a is thus dependent on the angle of rotation β.

While in the device shown in Fig. 3 the angle a e.g. Was 15 °, i.e. a = 15 °

applies, the angle a results in the correct sign by the above equation (I)

a = f (ß) + 15 °

Taking f (ß) e.g. once arbitrarily to -40 °, the result is (a to -35 °. However, the angle of rotation ß itself is somewhat larger than 40 ° in the example shown, so that the function f (ß) is approximately -3/4 ß.

A very suitable angle for a for many practical cases is thus calculated from the equation a = -3/4 ß + 15 ° (III)

where ß is used as a positive numerical value.

However, the size f (ß) is not limited to -3/4 ß, but in practice covers at least a range of 1/3 ß to 1 ß. The angle a shown in FIG. 3 is also not limited to 15 degrees, but in practice can have values between + 15 ° and -10 °, based on the straight line 304

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in Fig. 3 assume. Taking this fluctuation range into account, the equation for a is a = f (ß) + (15 ° -x) (IV)

where x is an arbitrary angle, which in practice is mostly between 0 ° and 25 °.

The equation based on the angle β could also be based on the angle S, because the relationship β + 8 + 90 ° = 360 ° or β + 8 = 270 ° exists, i.e. 8 = 270 ° - ß.

The straight line 305 shown in FIG. 3 passes through the corner points 24 and 30 of the profile 3. These function points correspond functionally to the corner points 901, 902 and 904, 905 of the profiles 910 and 911 of FIG. 8. For the sake of clarity 8, this straight line was not placed on the profile 3 but on the profile 910.

It can also be seen from FIG. 8 that the size b also depends on the angle of rotation β. The straight lines 303, 302 do not run parallel to the straight line 305 because they are determined by the position of the corner points (e.g. 28, 19) of two different profiles 2, 3. The angle which the straight lines 302, 303 form with the horizontal line 800 is left-turning - compared to the corresponding angle in FIG. 3. This angle, which determines b, can be expressed as a function of ß.

Claims (17)

Claims 1.Device for automatically controlling the incidence of light in a room, with several light-guiding profiles (2, 3; 38 to 55; 400, 401; 501 to 505), through a first rectilinear and external escape (300) and through a second rectilinear and inner flight (301), which runs parallel to the first flight (300), are limited and have an upper side (21, 31; 402, 403; 506, 507) that is opposite a first adjacent light-guiding profile (2) and one Have underside (22, 32; 60, 33), which is opposite a second adjacent light guide profile (3), the light guide profiles (2, 3; 38 to 55; 400, 401; 501 to 505) at least on an area facing the incident light (21) mirrored and the relative positions of the light directing profiles (2, 3; 38 to 55; 400, 401; 501 to 505) to one another are unchangeable, and that at least the top (21, 31; 402, 403; 506, 507) one each of the light directing profiles (2, 3; 38 to 55; 400, 401; 501 to 505) at least e in concave mirror section in cross section, that the underside of a light guide profile (2, 3) consists of at least two reflector parts (22, 32 or 60, 33), the connection point (18, 30) of the mirror part of the top (21) of an adjacent one Light directing profile (2, 3; 38 to 55; 400, 401; 501 to 505), characterized by the combination of the following features: the distance (a) between the outer flight (300) and the inner flight (301) is equal to or less than 10 mm; the angle of inclination a of a straight line (305) to a perpendicular (304) through both alignments (300, 301) is given by the relationship a = f (β) + (15 ° -x) where f (ß) is a function dependent on the angle of inclination ß of the perpendicular (304) to the surface of the earth and x is an arbitrary angle, and this straight line (305) is defined by a point of contact (24, 28) between the outer flight (300) with one of the light guide profiles (2) and through the connection point (18, 30) between the two reflector parts (22, 32 or 60, 33) of the underside of this light guide profile (2, 3; 38 to 55; 400, 401; 501 to 505 ) goes; the maximum shadow width (b) of a light guide professional (2, 3; 38 to 55; 400, 401; 501 to 505) is 10 mm, this shadow width (b) being defined by two parallel straight lines (302, 303), of which the one straight line (303) passes through the point of contact (17) between this light directing profile (2) and the inner flight (301), while the other straight line (302) passes through the point of contact (28) between this light directing profile (2) and the outer flight (300) and on the other hand through the point of contact (19) between a light-directing profile (3) adjacent to this light-directing profile and the inner flight (301). 2. Device according to claim 1, characterized in that f (ß) = -1/4 ß to -2 ß. 3. Device according to claim 2, characterized in that f (ß) = -3/4 ß. 4. The device according to claim 1, characterized in that when the device is used as a facade element arranged perpendicular to the earth's surface, 0 ° <a <15 °. 5. The device according to claim 1, characterized in that the tangent (308) passing through the connection point (18, 30) between the two reflector parts (22, 32) and resting on the outwardly directed section has a straight line (309 , 800) forms an angle y which does not exceed 30 °. 6. The device according to claim 1, characterized in that an opaque element has three corner points (17, 18, 28). 7. The device according to claim 6, characterized in that a discontinuity (414, 415) is provided between two (17, 28) of the three (17, 18, 28) corner points. 8. The device according to claim 7, characterized in that the discontinuity (414, 415) is formed by the transition from a concave surface (402, 404) to another concave surface (403, 405). 9. The device according to claim 7, characterized in that the discontinuity is formed by a surface (516 to 520) which connects two concave surfaces (506, 507; 508, 509) with each other. 10. The device according to claim 8, characterized in that two first corner points (17, 28; 19, 24) lie in an upper concave surface (31, 21) which is directed towards a light source, while two second corner points (28, 18; 24, 30) lie in a lower surface (32, 33) which faces the light source and that two third corner points (18, 17; 30, 19) lie in one surface (22, 60). 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 8th 15 CH 686 050 A5 gene, which is directed into the interior (4), wherein the lower and directed towards the light source surface (32, 33) has a tangent (308) having an angle of less than 30 ° with a horizontal axis (309, 304) having. 11. The device according to claim 1, characterized in that the profile cross-section of a light guide profile (2, 3) has an area which is less than 30 mm2. 12. The device according to claim 10, characterized in that the upper concave surfaces are parabolic surfaces and have two individual parabolic pieces (402, 403; 404, 405), the parabolic axes (410, 412) of which have different inclinations, the parabolic axis (412) of the first individual parabolic section is steeper than the parabolic axis (410) of the second individual parabolic section is inclined. 13. The apparatus according to claim 1, characterized in that the opaque elements (601 to 606) are embedded in transparent material (607) which has a refractive index that is greater than or equal to the refractive index of water. 14. The apparatus according to claim 13, characterized in that the light-guiding profiles (601 to 606) embedded in transparent material (607) form a laminated glass pane with two transparent panes (608, 609). 15. The apparatus according to claim 1, characterized in that only one surface (21) of the light guide profiles or a portion of this one surface (21) is mirrored and that the other surfaces (32, 22; 33, 60; part of 21) reflect diffusely are trained. 16. A method for producing a light directing profile (2) for a device according to claim 1, wherein said light directing profile (2) has at least three corner points (17, 18, 28) in cross section, between which there are straight or curved surfaces (22, 31, 32 ), characterized in that the light directing profile is produced from a solid steel or metal wire by rolling, which has a diameter of less than 6.5 mm. 17. A method for producing a light-directing profile (2) for a device according to claim 1, wherein said light-directing profile (2) has three corner points (17, 18, 28) in cross section, between which there are straight or curved surfaces (22, 31, 32). are located, characterized in that the light directing profile (2) is produced by injection molding. 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 9