FI81663C - Optical arrangement for lighting apparatus - Google Patents

Description

1 81663

Lamp optics arrangement

The invention relates to an optical arrangement of a luminaire, in particular a signal, having a zoned concave reflector and a zoned prism in the light aperture of said reflector and a relatively point light source for shaping and has a uniform radiation intensity.

Optical solutions are known in which the light emitted by a lamp placed in a suitable position is directed by means of a reflector and a prism or lens part placed in the light opening of the reflector. The reflector is most commonly rotationally symmetrical, in which case its function is to form a beam of light parallel to the rays hitting the reflector from the lamp. This is also the case when the light coming directly from the lamp to the prism is aimed, by means of the prism or lens part, in the desired manner at a certain space angle. Unless special reflector lamps are used, such as the so-called bucket lamp, all these structures have the common disadvantage that the radiation beam is circular in cross section and that the radiation intensity in this beam is very difficult to obtain evenly. Typically, the intensity peaks at the center of the radiation beam, from where it gradually decreases as you go to the edges of the beam. In addition, a considerable part of the total amount of light emitted by the lamp becomes useless stray light. With said special lamps, ta. by using several reflectors connected in series, the light beam is limited to only one edge or the devices become very large. Another disadvantage is that due to the unevenness of the light emitted by the lamp, there are also similar unevennesses in the intensity of the radiation beam in addition to the above-mentioned light distribution error.

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It is, of course, clear that the light emanating from the lamp can be divided into a space space of circular cross-section of the desired cross-section with a constant intensity when using, for example, optical arrangements familiar from projectors or the like. However, such arrangements lead to solutions of such size and cost in the use of luminaires, and in particular in light signals, that the application of these principles is out of the question.

Several different attempts have been made to solve the problems described above. Irregularities in the radiation beam can be eliminated in a simple manner by using a small random irregularity evenly distributed over the surface of either a mirror, such as U.S. Pat. No. 3,597,606, or a prism or lens gun, such as frosted glass. Although this solution compensates for the differences in intensity, at the same time it causes a considerable increase in stray light and thus degrades the efficiency of the luminaire. This does not affect the cross-sectional shape of the light beam, but makes it more difficult to delimit it, for example, into a rectangle. One application of these is disclosed in U5-4 337 507, in which the reflector forms a beam of radiation precisely delimited at one edge, which is aligned with a lens part placed in front of it, the function of which corresponds to that of frosted glass. Again, it has not been possible to delimit the spotlight on all four sides.

In the previous F1 patent application 870061, an attempt has been made to improve the efficiency by placing the lamp so that its base points towards the light aperture of the reflector and by placing a prism in the light aperture which directs the light in one plane. With this solution, the efficiency is relatively good, but the radiation beam does not become very well limited, and especially in the uniformity of the radiation in the cross-sectional area of the beam, there is room for desire.

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U.S. Pat. No. 2,574,031 discloses an arrangement which seeks to illuminate a desired area evenly, which means an evenly distributed intensity over a certain space angle. In this arrangement, however, the shape of the light source must be consistent with the desired shape of the area to be illuminated, which alone makes the implementation of the solution very cumbersome or at least leads to poor efficiency if the light source is delimited by e.g. mechanical means. This solution also uses a unitary mirror to provide a parallel beam of light, which is then directed both vertically and horizontally by at least two lens plates containing a large number of differently spaced lens elements.

In addition to the above-mentioned drawback of this structure also leads to a relatively large size and complex linesilevyjen therefore also expensive construction.

The object of the invention is thus to produce, on all four sides, a well-defined, te. a radiation beam of rectangular cross-section with a uniform luminous intensity. It is a further object of the invention that a relatively point-like, te can be used as the light source. compared to the dimensions of the reflector and the prism part, a small, light body, for which, however, no other requirements need to be imposed, for example with regard to shape or radiation uniformity. It is a further object of the invention to provide an optical arrangement which transmits the radiation of a light body to the light beam with the best possible efficiency, so that the proportion of possible stray light is very small. It is a further object of the invention to provide an optical arrangement which meets the above requirements and which is small in external dimensions, simple in structure and thus inexpensive to manufacture.

By means of the optical arrangement according to the invention, a decisive improvement in the above-mentioned drawbacks is achieved and the above-mentioned objects are achieved. To achieve this, the arrangement according to the invention is characterized by what is set forth in the characterizing part of claim 1.

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The main advantages of the invention can be considered to be that of a conventional light source, te. from an incandescent lamp, the incoming radiation can be transferred with extremely good efficiency to the currently desired radiation beam with a very uniform radiation intensity in the cross section. Another advantage of the invention is that this can be achieved mechanically with a very simple and reliable structure, whereby the result is mechanically strong and economically advantageous. The arrangement is thus also suitable for several uses, but especially for different signs.

In the following, the invention will be described in more detail with reference to the accompanying drawings.

Figure 1 shows an optical arrangement according to the invention in an axial section of a luminaire.

Fig. 2 shows an arrangement according to the invention in a plane perpendicular to the axis of the luminaire perpendicular to the plane of Fig. 1.

Figure 3 shows an overview of a reflector according to the invention in the axial direction of the luminaire from the light aperture towards the reflector.

Fig. 4 shows an overview of the prism part seen from the same direction as the reflector of Fig. 3.

Figure 5 shows the principle of operation of the mirror zone of a reflector according to the invention.

Figure 6 shows the principle of operation of a multi-zone reflector according to the invention.

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Figure 7 shows the principle of operation of a single lens zone of a prism & part according to the invention and the operation of a prism part consisting of several zones.

Figure 1 shows in general the optical arrangements of the luminaire indicated by reference numeral 1. Figure 2 also shows the optical arrangements of the lamp 1 in its entirety, but in a direction perpendicular to the section of Figure 1. The optical arrangement of the lamp consists of a concave convex reflector 2, a light source 3 and a prism part 4 placed in the light aperture of the reflector 2. More specifically, Fig. 1 is a section of the lamp along the plane of symmetry T1. which is the plane of symmetry of the mirror 2, as shown in Fig. 3. The above means that the prism part 4 refracts light only symmetrically towards or away from its optical plane T1, but not in the direction of this plane T1 when the light source is also in the plane T1. Correspondingly, the plane of symmetry T2 of the mirror is the optical plane of the mirror, whereby the mirror reflects light symmetrically towards the plane T2 or away from the plane T2 when the light source is at this plane T2. The line of intersection of these planes T1 and T2 forms an effective optical axis 5, which is thus not a conventional optical axis, since neither the mirror nor the prism portion are rotationally symmetrical, but a line corresponding to the optical axis formed as the line of intersection of the optical planes. However, the following is used in this line 5 as the optical axis.

Figure 3 shows the reflector 2 in the direction of the optical axis 5 from the outside of the device towards the light source. Fig. 4 shows only the prism part 4 in the same direction. It can be seen from Figs. 1-4 that the trough-shaped reflector and the prism part of the device are located so that their optical planes T1 and T2 are perpendicular to each other, te. crisscross. In addition, the prism portion 4 is located in the light aperture 6 of the reflector 2, which is thus rectangular in shape, like the desired radiation pattern. In addition, the ends of the trough reflector 2 are closed by plates 7a, 7b, which are preferably arranged symmetrically on both sides of the lamp 3 and further so that they move away from each other when moving from the bottom 9 of the reflector 2 towards its light opening 6. The shape and position of the plates 7a, 7b are not essential for the operation of the lamp 1. In addition, it should be noted that the radiating part of the light source lamp 3 is always located mainly on the optical axis 5 and preferably so that the base of the lamp is directed towards the light aperture, the maximum intensity being directed towards the reflector 2. According to the invention, the radiating surface of the lamp may be relatively small, which in this context means that the maximum dimension of the light-emitting surface of the lamp may be less than one tenth of the largest cross-section of the reflector and the prism part. The invention makes it possible to use an even smaller light body, e.g. 1/50 part.

It can also be seen from Figures 1 to 4 that the reflector 2 consists of zones P1, P2, P3, P4 symmetrically arranged on both sides of the optical plane T2. Similarly, it can be seen from Figures 1 to 4 that the prism portion 4 is formed symmetrically from the prism zones L1 and L2 located on either side of its optical plane T1. The internal functioning and interaction of these zones are described in more detail below. Figure 5 shows a schematic view of one of the zones Px of the mirror, where x can in itself have any value depending on how many zones the mirror is divided into. The examples in Figures 1, 3 and 6 have four different zones and thus, for the sake of symmetry, a total of eight zones, of which always two are pairwise symmetrically similar. The mirror surface belonging to the zone Px is thought to be formed as follows. The mirror surface is thought to consist of mirror elements No. Figure 5 shows a situation where the value of i varies between 1-9. If you want the mirror to reflect from a light source 3

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7 81663 to the taeok angle of the incoming radiation ai, te. according to the invention, the beam of the mirror elements Ei according to the invention reflects the beam from each of the lamps 3 to each element in the direction Si, which forms an angle 3i with respect to the plane T1, at an angle +0 (1/2 with respect to the plane T2 on one side thereof and a 1/2 on the other side Then each mirror element Ei should reflect the beam coming from this light source 3 to this element at an angle β i, where α 1 <A) fti = al / 2 - <il> * / <N-1>, or alternatively ai <B> β i = - a 1/2 - <i-1> * / <N-1), where N is the integer number of elements i. In the example of Figure 5, where N = 9 and the angle 3i implements the equation <A>, the element E1 reflects the angle βΐ = + ai / 2 the element E2 in the direction 32 = α1 / 2 - al / 8, the element E3 in the direction β3 = al / 2 - αΐ / 4, etc. Element E5 reflects in the direction of the optical axis T5, where 35 = 0, etc. until the last element E9 reflects at an angle of 3g = - <* 1/2. If the angle βί implements the equation (B> the reflected rays intersect, the element E1 would reflect at an angle 3i = - <* i / 2, the element E5 further in the direction of the optical axis and the element E9 at an angle β9 = + α 1/2. Zone P2 in Figure 1 is depicted as a zone according to Equation <B> while zone P4 in Figure 1 as well as Figure 5 show a solution according to Equation <A). Thus, the zone Px reflects the radiation from the point light source 3 against the plane T2 at an angle perpendicularly ai evenly distributed, whether it is a mirror surface according to either equation <A) or (B). In practice, there are significantly more elements Ei in the zones than the nine shown in the example, each number chosen only to illustrate the mode of operation. In practice, the mirror zone may indeed consist of a large number of mirror elements as mentioned above, in which case the number may be 50, 100, 200 or some other number. The shape of the surface of the mirror zone Px can also be defined as continuous by allowing the total number N of its elements Ei to grow to infinity and the size of the element to close to zero. This results in a flat continuous mirror surface, which has the property already mentioned above that β 81663 it reflects the rays coming from the light source evenly to the desired angle. The edge radii S1 and SN of the mirror zone thus define the light beam in a direction perpendicular to the optical plane T2.

Figure 7 shows e.g. the operation of the prism part which is analogous to the operation of the mirror part. You. the beam from the light source 3 is refracted in one exemplary zone Lz of the prism portion 4 so that a beam of light emits from each of the prime elements Pj of the zone in the direction Sj forming an angle 6j with respect to the optical plane T1, where <C> = a2 / 2 - <j-1> * a2 / (M1>, or alternatively (D) Sj = - a2 / 2 - C j-1> * a2 / <Ml>, where M is the integer number of the elements j. / 2, the next radius S12 in the case of the example where M is 9 and the angle 6j implements the equation <C), in the direction 62 = a2 / 2 -a 2/8, etc. further, the radius S15 to the angle 65 = 0, te. in the direction of the optical axis 5, etc. until the radius S19 at the other edge is oriented at an angle 69 = - (X2 / 2. If the angle 6j holds the folded rays passing crosswise after the prism of equation (0), the radius S11 travels in the direction 61 = and a second edge radius S19 in the direction $$ = + <* 2/2 The refraction in the prism according to equation (D) is shown in Fig. 2. Thus, the prism zone Lz distributes and directs the light from the light source 3 evenly to an output angle α2 perpendicular to the plane T1. whichever of the equations <C> or <D) the solution is. As in the mirror case, the prism part 4 can be shaped as described from the folding prism elements, whereby the result resembles the so-called A Fresnell lens, however, is not really such, but is indeed made up of a large number of different prism elements. As in the mirror case above, by allowing the number M of prism elements to increase to infinity and the size of the elements

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9 81663 send zero to obtain a flat continuous lens surface as imaginatively marked with a dotted line 8 in Fig. 7. Since such a full material lens would be very thick and difficult to manufacture for most purposes, this is reduced in most cases according to the Presnell lens principle, as in zone 7 for zone L2. . The zone L1 in Fig. 7, on the other hand, is a smooth-surfaced lens obtained by following the procedure described above. The Fres-nell lens orthodontically obtained in the latter way is not completely identical to the previously mentioned prism part consisting of prism elements, but both are in principle useful.

The surfaces of the mirror zone Px and the prism zone Lz, defined as continuous surfaces as described above, are not normally spherical surfaces in the general case or circular cylinder surfaces in the case of the invention, but other continuous surfaces. For practical implementations, the surfaces can be replaced by circular cylinder surfaces fitted as closely as possible to the calculated surface. In this case, the manufacturing technology becomes simpler and the accuracy of the result is sufficient for most applications.

Figure 6 shows the other side of the mirror 2 according to the invention. The other side of the mirror is mirror-like on the other side of the plane T2. In this example, the mirror zone P1 uniformly reflects the radiation from the light source 3 to the desired output angle α 1, likewise the mirror zone P2 evenly reflects to the desired angle α1, the mirror zone P3 likewise reflects evenly to the angle α 1, and the zone P4 likewise. Thus, each mirror zone operates independently of each other according to Figure 5 and the corresponding description. Since there are other corresponding mirror zones P5-P8 on the other side of the plane T2, it is obtained that the radiation from the light source 3 is reflected in eight different zones at one and the same output angleα i, te. a double "coverage" is obtained at the starting angle α1 of 10 81 663. The result is an extremely even distribution of light across the cross-section of the beam, because if the unevenness of the light source when reflected through a mirror zone causes unevenness at some point in the beam, the unevenness cannot in any case be The edges of the radiation beam also become very precise because the edge radii of all the zones overlap. Thus, very little stray light is also generated. The number x of zones Px can be selected as desired according to the application, the uniformity of the light source, and different requirements.

The prism part 4 is shaped analogously to the mirror 2, as can be seen in Fig. 7. In this case, the prism part consists of a total of three zones, te. the central zone L1 and the two symmetrical zones L2 and L3, which are mirror-shaped with respect to the plane T1. In this case, the zone L1 emits evenly distributed radiation to the starting angle α2 and likewise both zones L2 and L3 to the same starting angle α2. Thus, in this case, the prism part 4 gives a triple "coverage" at one and the same starting angle «2. As in the case of a mirror, the unevenness caused by the inaccuracy of the light source can be compensated and the intensity in the radiant beam can be very uniform and the limits of the radiation beam precise and the stray light small. The number z of the zones Lz can be selected as desired, as in the mirror, depending on how uniform the light source 3 emits and how large the uniformity requirements are.

Since the optical planes T1 and T2 are positioned perpendicular to each other and since, as described above, both the mirror and the prism portion emit uniformly distributed light beams in perpendicular sy-1inter coordinate systems, they interact because the prism portion was placed in the light aperture 6 of the mirror portion 6 as previously described. a beam of rectangular cross-section, the intensity of which is extremely uniform at different points in the cross-section.

In a practical implementation, all the mirror zones Px may be according to Equation (A) or according to Equation (B), or some of the zones may be according to Equation (A) and some according to Equation <B>. Correspondingly, the prism zones Lz may all be according to Equation (C) or according to Equation <D), or some of the zones according to Equation <C) and some according to Equation <D). All of these different mirror zone key combinations work with all different prism zone combinations. The result is always a spotlight that meets the requirements, only the shape of the luminaire varies.

Due to the dimensional requirements of the application or for other reasons, in both the prism section 4 and the reflector 2, the prism zones Lz or the mirror zones Px, respectively, can be connected to each other via steps between them and in the direction of the respective optical plane. Such steps 10a, 10b, 10c parallel to the plane T2 are shown in Fig. 6 between mirror zones P1 and P2, zones P2 and P3 and zones P3 and P4, respectively. The steps do not substantially affect the optical performance of the arrangement, but it allows the diameter of the reflector and thus the entire luminaire to be significantly reduced in a direction perpendicular to the plane T2. Although the thickness of the lamp in the direction of the optical axis 5 then slightly increases, but as a whole the dimensions are better e.g. suitable for the signal. Other types of total dimensions can be calculated for other applications. In the prism part, the zones can not only be displaced in the above-mentioned manner by steps in the direction parallel to the optical plane T1 of the prism part, but also tilted against the plane T1 from the perpendicular direction to form another desired angle therewith.

Claims (15)

12 81 663 £ atgnUi claims An optical arrangement of a lamp, in particular a signal, comprising a zoned concave reflector (2) and a zoned prism portion (4) in the light aperture <6) of said reflector and a relatively point light source (3) on the optical axis formed by the reflector and the prism portion (5> to provide a well-defined beam of radiation having a substantially rectangular shape in the cross-section of the optical axis and a uniform radiant intensity, characterized in that the light is balanced in the first transverse direction against the optical axis (5) at least almost exclusively by a trough-shaped reflector (2); CPx) is designed to distribute the radiation from the light source (3) evenly in this direction to the desired output angle (a 1) and thus give the radiation pattern at least one full opacity, whereby the number of mirror zones <x> determines the number of opacity times in this direction. that, in addition, the equalization of light in the second direction perpendicular to the first direction and transverse to the optical axis takes place at least almost exclusively by means of the prism portion <4>, that each zone <Lz> of the prism portion is designed to distribute the radiation from the light source (3) evenly in the desired angle (a 2) and thus give the radiation pattern at least one full opacity, wherein the number of prism zones (z) determines the number of opacity times in this direction. An arrangement according to claim 1, characterized in that each zone <Px) of the reflector <2> is shaped as a concave cylindrical mirror such that the mirror element (E1) closest to the optical axis in the zone and the mirror element (EN) furthest from the optical axis in the zone ) reflect the corresponding rays from the light source (3) into edge rays of the illumination angle (ai) intersecting behind or alternatively in front of the mirror surface of the zone in question, and that the intervening mirror elements always reflect their optics near the axis in the order of Mull 13 81 663 at an angle between the rafter artwork at most at regular intervals from the direction to the other edge radius. Arrangement according to claim 2, characterized in that in each mirror zone <Px> each mirror element (Ei) reflects in the direction (Si) of the beam from the light source which forms an angle (βί) with respect to the optical plane <T2) of the reflector, this angle at least approximately equation (A) 3i a otl / 2 - <i - 1) * ai / (Ni> or alternatively equation <B> 3i * - al / 2 - <i - 1> * al / (Nl), where i gets the values 1: to N. Arrangement according to Claim 3, characterized in that (N) is a finite quantity or a large number, and in that the surface of the mirror zone <Px) follows at least approximately the calculated path of the mirror elements (Ei). Arrangement according to Claim 3, characterized in that the number of mirror elements (N) is infinite or almost infinite and that the surface of the mirror zone (Px) is shaped to correspond at least approximately to this calculated shape. Arrangement according to Claim 5, characterized in that in one or more mirror zones (Px) the surface of this region of the mirror part is shaped as a circular cylindrical surface which approximately corresponds as closely as possible to the calculated continuous surface shape of this zone. Arrangement according to claim 1, characterized in that each zone (Lz) of the prism part (4) is shaped as a convex or convex-like Eylindrical lens such that the prism element (F1) closest to the optical axis in the zone and furthest from the optical 14 81 in the zone The prism element (FM) on the 663 axis refracts the corresponding rays from the light source (3) into edge rays of the illumination angle << * 2> intersecting behind or alternatively in front of the prism part of the zone in question, and that the intervening prism elements are always close to the optical axis away from it, fold at a corresponding angle between the edge radii in order from the direction of the first edge radius to the direction of the second edge radius at regular intervals. β. Arrangement according to claim 7, characterized in that in each prism zone <Lz) each prism element (Fj) refracts in the direction (Sj) of the beam from the light source which forms an angle (6j> with respect to the optical plane <T1) of the prism part, this angle being at least approximately follows the equation (C> 6j = a2 / 2- (jD * a2 / (Ml) or alternatively the equation <D> = -a2 / 2 - <j - 1> * a2 / <Ml), where j is given the values 1: from M to M. Arrangement according to Claim 8, characterized in that the number (H) of the prism elements is a finite or large number and that the surface of the prism zone <Lz> follows at least approximately the calculated course of the prism elements (Fj). An arrangement according to claim Θ, characterized in that the number of prism elements <M) is infinite or nearly infinite and that the surface of the prism zone (Lz) is shaped to correspond at least approximately to this calculated shape. Arrangement according to Claim 10, characterized in that in one or more prism zones (Lz) the surface of this region of the prism part is formed as a surface formed by a circular cylinder or cylinders which approximately corresponds as closely as possible to the calculated continuous surface shape of this zone. Il 15 81 663 Arrangement according to Claim 10 or 11, characterized in that the prism zone is formed as a Fresnell lens in a manner known per se from a uniform continuous calculated surface shape. Arrangement according to one of the preceding claims, characterized in that in the reflector (2> and / or in the prism saw <4> the adjacent zones <Px and / or Lz) are associated with the respective respective optical level <T2 or resp. By means of steps <10 a-c> parallel to each other in order to make the external dimensions and shape of the luminaire suitable for the intended use. Arrangement according to one of the preceding claims, characterized in that the total number of mirror zones (Px) (x>) is at least four arranged in pairs on each side of the mirror optical plane <T2) and that the total number of prism zones (Lz) is <z>. Arrangement according to Claim 14, characterized in that the total number (z) of the prime zones (Lz) is three or other odd numbers greater than this, one zone <L1) being arranged symmetrically across the optical plane (T1) of the prime part and the rest (L2, L3). ) in pairs on both sides of this plane. 16 81 663