JPH10214507A - Reflector, and lighting system equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reflect light after passing a nearby light source, by making involutes, having a total of four branch sides in profile, and directed to two reverse directions, belong to one leg of a light source respectively, and be arranged axially symmetric with respect to the axis of symmetric. SOLUTION: An electrodeless fluorescent lamp 52 is composed of a straight pipe discharge tube forming a closed loop composed of two long legs 54 and 56 and two short joining parts 58 and 60. The joining parts 58 and 60 are enclosed respectively by transformer ferrite cores 62 and 64 equipped with coils, a lamp 52 is fixed into a reflector inside by the cores 62 and 64,c and the long legs 54 and 56, are arranged parallel to the axis of the trough type reflector 51. The short side surface 55 of the reflector is made a mirror surface, and a reflector profile is composed of the long branch side extending from the apex S1 to the opening part in the place of a line including a point A. The short side branch is positioned between the long legs 54 and 56, and is extended from the top point S1 to a line including the end point D in the place of a light outgoing port. A simple curved shape can also be used instead of the short branch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a reflector for an elongated or annular light source having two legs,
The reflector relates to a reflector wherein the contour of the reflector is formed at least in part from an involute section, the two sections contacting at the apex.

According to the invention, a particularly large light source, in particular a multi-leg or ring-shaped fluorescent lamp or a similarly formed electrodeless microwave excitation lamp (cf. DE-A 260 01 666). Reflectors for elongated light sources are of interest. In the following, the concept of a light source also includes a radiation source emitting infrared or ultraviolet radiation.

[0003]

BACKGROUND OF THE INVENTION Published German Patent Application No. 275
A trough reflector is known from U.S. Pat. No. 5,253,537, which is used for elongated tubular light sources, in particular fluorescent lamps, and whose cut line is formed in part by two adjacent involutes (see below). . The two involute branches do not touch each other at all and either terminate on the light source, strictly at the light outlet behind the light source, or at a certain distance from the light source behind the light source (with respect to the light outlet). Contact with distance. This intersection of the two involutes is referred to below as the vertex.

[0004] According to EP-A-442246 used for straight-tube light sources, the cut line is two.
Completely similar reflectors are known which form two mirror-symmetric involute branches, the vertices of which are also located exactly behind the light source and exactly on the normal to the light exit.
The involute migrates to a parabolic branch toward the light exit.

[0005] However, this type of technique, which is suitable for a single leg light source, is not suitable for an elongated light source having two legs. This is because such a reflector can no longer reflect all the light past the light source.

[0006]

SUMMARY OF THE INVENTION The object of the invention is to provide a reflector of the kind mentioned at the outset in which, even in the case of an elongated light source with two legs, all the light is reflected past the light source. Is to provide. Another object of the present invention is to provide a lighting fixture having such a reflector.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an involute section having a total of four involute sections, each of which has two oppositely directed involutes, each belonging to one leg of the light source, The arrangement is rotationally symmetric or axially symmetric with respect to the axis of symmetry passing through the center between the legs, the vertices being located approximately on a straight line connecting the centers of the legs, thereby each having one long involute section (branch) and one short Involute section (side)
Is solved by a reflector belonging to one leg.

[0008] A particularly advantageous configuration of the reflector is claim 2.
To 9 are described.

[0009] Also, the latter problem described above is an illumination in which the light source is constituted by a lamp in which the glass sphere has two parallel legs and the reflector is a trough reflector having two long sides and two short sides. Solved by equipment.

When radiation emitted from an extended light source is reflected back onto the light source, a portion of that radiation is generally lost by absorption. In the following, it is used for a radiation source with two legs with a circular or elliptical or similar cross section (eg a compact or U-shaped fluorescent lamp), which reflects all light past the light source and therefore A reflector that avoids loss due to self-absorption will be described. In the simplest case, no other conditions are considered, except for the requirement that the radiation not be reflected back to the light source. In this case, the reflector has the characteristic of having as small a dimension as possible. In particular, the angular distribution of the radiation intensity (Indicatrix) continues to be open. This angular distribution can be adjusted by the appropriate deviation from the reflector profile described above. That is, the computational principles described here provide a limit curve which can in fact be adapted to the respective application, in which case a compromise can be made with regard to efficiency and / or reflector size. In the vicinity of the light exit, the cut contour of the reflector can be described, for example, by a parabola or an oblique plane.

For a better understanding of the present invention, a detailed description of the characteristics of the involute reflector must first be provided.

The basic concept has been known for some time, and will be described with reference to FIG. The radiation source 1 has a circular cross section with a radius R. The radiation emitted from this radiation source 1 is reflected completely past the radiation source if the cut line of the reflector is involute (a simple derivation of this helical curve is described, for example, in the publication "The Lihting".
Journal ". Seelensen, "Design of Optical System for Luminescent Body (Design of
Optical Systems for Lumin
aires) "). Involute satisfies the conditions that apply to each part of the reflector. Light source 1
The marginal rays emitted tangentially from point K on the surface of the surface in the direction of any reflector point L must be reflected to the right beside the light source. To that end, all other rays emitted from the light source towards the point L will reach the limit point M located on the opposite side of the light source, the limit rays emitted from this limit point M (indicated by dashed lines) First), including the light source, is reflected to the right. In the extreme case of providing the smallest possible reflector shape, the light ray KL is reflected back to itself. According to FIG. 1, this gives the mathematical definition of this limit curve in the following differential form:

[0013]

Dφ = [(1 / R) ² − (1 / r) ² ] ^1/2 dr

Note that φ and r are the curved coordinates of the reflector curve. The reflector curve itself, which is as small as possible, is obtained by means of the graphical or mathematical integration of equation (1). This solution is given in closed form.

[0015]

２ (r) = Φ ₀ ± ｛[(r / R) ² -1] ^1/2
+ Arccos (R / r)｝

Φ ₀ gives the starting point of the involute on the surface of the light source. For the above discussion, it has been assumed that the lamp axis is located at the coordinate origin (r = 0). The magnitude Φ ₀ is hereinafter referred to as the rotation angle.

In the simplest case, a spiral (see FIG. 1) starting radially from the light source surface (point B) is provided. This spiral is called involute by experts. This involute clearly belongs around the periphery of the lamp cross-section and thus generally at its radius R.

In general, reflectors having dimensions larger than the minimum dimension can also be used.

[0019]

Dφ ≦ [(1 / R) ² − (1 / r) ² ] ^1/2 dr

With respect to the involute described above, in principle, any section can be selected as a reflector. In particular, sections that do not hit the surface of the light source can be used. A mirror image, ie, an involute that opens in the opposite direction, can also be used as an auxiliary.

For a known example of a monopod light source, FIG. 1 shows, by way of example, a reflector 2 used for a light source 1 having a circular cross-section and whose cutting line 3 satisfies the conditions described above. Of the two oppositely extending involute branches 3a, 3b, curved portions AB, BF are used. The light exit 4 (a plane connecting the points A and F) is located at the height of the lower edge of the lamp. Therefore, such devices radiate only into the lower half space. The two involute branches were joined such that the two involute branches start from the lamp surface at the vertex or common point B. Such a device would theoretically have the smallest dimension of such a reflector width b and height h, ie b = 6.3R, h =
Provides 2.5R.

In practice, two oppositely extending involute branches whose vertices are located above the surface of the light source are used.

According to the invention, the above principles can be applied to lamps with two legs, with appropriate modifications.

To prevent light from returning to the light source despite the two legs, the cut surface of the reflector consists of a total of four involute branches. Each two involute branches belong to one leg of the light source. The arrangement with respect to the other legs is axisymmetric, with the axis extending centrally between the legs.

The vertices of the two involute branches belonging to one leg are not located behind the light source as in the prior art (ie, they are located almost on their normal line when viewed from the plane of the light exit port). ), Which is turned by 90 ° to the second leg. Here too, some play is permitted, whose size approximately corresponds to the angular diameter defined above. The vertex is therefore located between the legs. The length of both involute branches is very variable in this device. The opening angle of the longer involute branch is 180 ° or more, and the opening angle of the shorter involute branch is clearly 90 ° or less. In particular, the shorter involute branch is designed to prevent radiation from hitting the first leg to the second leg.

According to the invention, the reflector is a reflector for an elongated light source or an annular light source having two legs, the contour of the reflector being formed at least in part from an involute section. It is a reflector. In that case,
The two sections meet at the vertex. The contour has a total of four involute sections, of which 2
The two inverted involutes each belong to one leg of the light source. The device may be rotationally symmetric (for a ring lamp) or axially symmetric (for a long light source) with respect to an axis passing through the center between the legs, in which case the apex lies approximately on a straight line connecting the centers of the legs, Each one longer involute section (branch) and one shorter involute section (branch) belong to one leg.

The vertex S can be slightly shifted with respect to the connecting straight line. This vertex can generally be shifted by an angle ε = 10 ° to 20 °. Here, ε is the angle between the straight line SO (vertex-origin) and the connecting straight line between the legs.

The two longer involute branches as well as the two shorter involute branches usually make contact between the two legs. Both contact points form a (virtual) straight line representing the axis of symmetry of the reflector.

The profile of the reflector can have another section that makes the indicatrix of the outwardly emitted radiation better match the desired target. In particular, one further section is continued on the longer involute branch and can be embodied in particular as having a parabolic shape or as an oblique plane.

Preferably, a support or separating wall is implemented between the two legs in the reflector. This separating wall can in particular extend between the two contact points of the involute (see FIGS. 2B and 2D).

There are many possibilities for forming the separating wall. 1
In one embodiment, the separating wall has at least shorter involute branches as contours. In particular, the separating wall may include a region near the vertex of the longer involute as a contour. However, a portion of the shorter involute branch can be eliminated, and in particular, the shorter involute branch can be completely eliminated.

Frequently, the separating wall has a simpler profile than the involute, for example a diagonal or straight wall.

The reflector according to the invention can be used as a trough-type reflector for a luminaire in which the light source consists of a lamp whose glass sphere has two parallel legs. In that case, the lamp may be intended for an electrodeless lamp with a closed glass bulb, in which case the glass bulb may be a tube having an oval or substantially rectangular shape in plan view. Alternatively, a conventional fluorescent lamp with a U-shaped curved tube, or other light source, may be used.

In practice, of course, one must carefully consider whether the complicated construction of the separating wall between the legs can be simplified to favor poor lighting efficiency. For example, a portion of the shorter involute branch can be eliminated. Alternatively, in the separating area, the reflector profile is simplified or implemented only as a straight separating strip.

It is also possible to use, as light source, in particular a ring-shaped or two-legged electrodeless lamp in which the two legs of the lamp tube are joined together at both ends and thereby form a closed tube. Preferably, the closure tube is oval or chamfered rectangular. Lamps of this kind are described, for example, in PCT / EP96 / 03180. However, in principle any other radiation source with two legs is equally suitable.

Of course, a plurality of such reflector devices can be juxtaposed, in which case a lamp with four or more legs can in principle be used side by side.

[0037]

Next, the present invention will be described in detail with reference to several embodiments.

FIG. 1 has already been described in detail above.

FIG. 2 shows a first leg 6 with a long glass ball.
3 shows a reflector 5 according to the invention for a lamp having a and a second leg 6b. The reflector profile is composed of four involute branches 7a to 7d as a whole, of which the two oppositely directed involute sections 7a, 7b belong to the first leg 6a of the light source, while Two oppositely oriented involute sections 7c,
7d belongs to the second leg 6b of the light source.

The arrangement of the involute branch is as follows:
It is axially symmetric about one plane Z passing through the center between 6b. The two oppositely oriented involute sections 7a, 7b belonging to the first leg 6a of the light source have a common vertex C which lies on a straight line X connecting the centers of the legs 6a, 6b. The longer involute section (side) 7a and the shorter involute section (side) 7b that are located therefore belong to the first leg 6a, respectively. Similarly, mirror-symmetrically, however, the two oppositely oriented involute sections 7c, 7d belong to the second leg 6b of the light source, the longer involute branch 7c and the shorter involute branch 7d It has a common vertex E on the straight line X.

In such an arrangement, both legs 6a, 6b
The interval a between them is a = 2.1R, and the width b of the entire reflector is b = 1.
4.4R and height h are h = 4.6R.

The reflector contours here are the partial curves AB, B
C, CD, DE, EB and BF. These sub-curves are implemented so that radiation does not return to the light source.

However, the partial curves CD, DE, BC
And EB also ensure that radiation from one leg does not hit the other leg. Of course, in each case, it must be investigated how much light the reflector shape now complicated provides.

The two lower reflector sections CD, DE and possibly the upper reflector sections BC, EB can be at least partially eliminated, provided that the radiation is abandoned.

FIG. 3 shows a reflector which substantially corresponds to the reflector of FIG. However, the involute branches 10a, 10b belonging to the first leg 11a have another starting point on the surface of the glass bulb, corresponding to other smaller differences in the rotation angle. It should be noted that the dimensions a, b, h (= leg spacing, reflector width, height) are reduced. In this case, a
= 1.35R, b = 12.9R, h = 4.2R.
That is, a is the largest decrease. In other words, the closer the points C and E are to the surface of the glass sphere, the smaller the distance a between legs can be without reflecting radiation to the lamp.

The dimensions a, b, h given in FIGS. 2 and 3
Is a calculated value that does not consider the physical reflector wall thickness d. In practice, d or 2d should be added.
The thickness of the separating wall (see below) is not taken into account.

FIG. 4 shows the longer involute branch 1
4a is shown a reflector that has been modified to only reach the vertex C to the point T ₁ instead of reaching the light exit opening (point A), starting. Reflector profile sections from T ₁ to A as parabolic 14c (or, as an oblique plane 14d as shown in dashed lines in FIG. 4) are implemented. A separation band 16 is provided between the legs 15a and 15b, and its contour follows a part of the long involute branch partial curves BC and BE and a part of the short involute branch 14b, that is, the partial curves CD and ED. I have. The remaining portion of the shorter involute branch 14b has been eliminated.

FIG. 5 shows another embodiment of a rotationally symmetric or axially symmetric reflector, in which the vertices S ₁ and S ₂ are connected to the coupling line X.
Is located on a straight line inclined upward by about 10 °, and between both cut circles of the ring or between both legs 22a and 22b of the U-shaped glass sphere. Separation wall 20 has a contour including a substitute outline i.e. shaded 21b of the longer involute Edahen 21a of sections BS ₁ and shorter involute branches sides. In cross-section, the right half of the cut plane of the reflector is implemented rotationally symmetric or mirror image with respect to the left half.

FIG. 6A is a schematic plan view of the luminaire 30 viewed from the light exit port of the ring-shaped compact electrodeless fluorescent lamp 31 having the glass bulb 22. FIG.
Shows a similar luminaire 40 with a trough-shaped reflector and a U-shaped fluorescent lamp 44 with a coupling bend 41 (shown in broken lines) and a base 42 covered by a hood 43, respectively.

FIG. 7 shows a trough reflector 5 as described below in FIG. 8 (or, for example, also in FIG. 4 or 5).
FIG. 2 shows a plan view of a lighting fixture 50 composed of a fluorescent lamp 1 and an electrodeless fluorescent lamp 52 as viewed from a light exit. This luminaire comprises a container having two long sides 53 and two short sides 55. The fluorescent lamp 52 is mounted at the center in this container. This fluorescent lamp 52 is formed of a straight tube discharge tube forming a closed loop composed of two long legs 54, 56 and two short joints 58, 60. Couplings 58,60 are each surrounded by transformer ferrite cores 62,64 with windings, and the lamp is fixed in the reflector by the transformer ferrite cores 62,64. The long legs 54, 56 are arranged axially parallel to the axis of the trough reflector 51.

The short side 55 of the reflector is mirrored. Reflector contour and a longer involute branches sides extending from the top lines S ₁ to the opening where the line containing the point A. The shorter involute side is 5 legs
Located between 4,56 and extends from the apex S ₁ to the line containing the end point D where the light outlet. Instead of the shorter involute branch, a simple curve shape (for example, diagonal lines as shown in FIG. 5) can be used.

FIG. 8 is a sectional view showing a reflector 51 for an electrodeless fluorescent lamp 52 having two legs 54 and 56. The legs 54, 56 are joined by joints 58, 60 (60 not shown) with at least one ferrite core 62. The core 62 is fixed to the container by a support component 65.

In a specific implementation, an electrodeless fluorescent lamp is used as the lamp, which has a tube diameter of about 52 mm and has a power of 150 W, which is significantly greater than conventional fluorescent lamps. In a trough reflector formed entirely of four involute branches, the lamp achieves approximately 90% illumination efficiency, compared to about 70% for a conventional trough reflector. The reflector container has a width of about 350 mm and a height of 110 mm. The distance T between the lamp legs is about 33 mm. The reflector 51 is the smallest reflector whose vertices (or originally the top lines) S ₁ and S ₂ are located on the connecting straight line X and are directly mounted on the legs. The reflector profile is composed of two short and long involute branches 59a, 59b and 61a, 61b, respectively. The illustrated Cartesian coordinate system represents the size of the luminaire (unit: mm).

The use of a plane (or parabola) obliquely directed outward to improve the light distribution results in a luminaire having a substantially cosine-shaped light distribution.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the basic principle of involute.

FIG. 2 is a schematic sectional view showing a first embodiment of a reflector for a two-legged lamp.

FIG. 3 is a schematic diagram showing a second embodiment of the reflector.

FIG. 4 is a schematic view showing a third embodiment of the reflector.

FIG. 5 is a schematic view showing a fourth embodiment of the reflector.

FIG. 6 is a schematic diagram showing a first embodiment of a lighting device provided with a reflector.

FIG. 7 is a schematic view showing a second embodiment of a lighting fixture provided with a reflector.

FIG. 8 is a schematic view showing a fifth embodiment of the reflector.

[Explanation of symbols]

 5 Reflectors 6a, 6b Long Legs 7a-7d Involute Branches 10a, 10b Involute Branches 11a Legs 14a Long Involute Branches 14b Short Involute Branches 14c Parabolic 14d Diagonal Planes 15a, 15b Legs 16 Separation Zone 20 21a Long involute branch 21b Short involute branch 22 Glass bulb 22a, 22b Leg 30 Lighting equipment 31 Fluorescent lamp 40 Lighting equipment 41 Coupling curved part 42 Base 43 Hood 44 U-shaped fluorescent lamp 50 Lighting equipment 51 Trough reflector 52 Electroless Type fluorescent lamp 53 Long side 54, 56 Leg 55 Short side 58, 60 Joint 59a, 61a Long involute branch 59b, 61b Short involute branch 62, 64 Transformer ferrite core 65 Supporting parts

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Deiter Hoffmann Germany 86165 Augustsburg Boehringerscheutlase 23 (72) Inventor Ulrich Binder Germany 80803 Miyunchen Hertz-Oakshuitlase 46 (72) Inventor Rotar Hitsushike Germany 81737 Miyunchen Theodor-Alto-Schüthlase 6

Claims (10)

[Claims] 1. A reflector for an elongated or annular light source with two legs, wherein the contour of the reflector is formed at least in part from an involute section, the two sections meeting at a vertex. In the reflector, the contour consists of a total of four involute sections (2
1a to 21d), of which two oppositely oriented involutes (21a, 21b) respectively belong to one leg (22a) of the light source, the arrangement being rotationally symmetric or both legs (22a, 22b). ) Are axially symmetric with respect to the axis of symmetry (Z) passing through the center, and the apex (S ₁ ) lies approximately on a straight line (X) connecting the centers of the legs, so that each one long involute section (side) (21
a) and one short involute section (side)
A reflector characterized in that (21b) belongs to one leg (22a). 2. The reflector according to claim 1, wherein the vertex (S ₁ ) is located on a straight line inclined by about ± 20 ° with respect to the origin (O) with respect to the connecting straight line (X). . 3. The reflector according to claim 1, wherein the profile of the reflector has another section (14c) for improving the uniformity of the radiation. 4. The reflector according to claim 3, wherein the further section follows the longer involute branch and has a parabolic shape. 5. The reflector according to claim 1, wherein a separating wall (20) partially including an axis of symmetry is arranged between the two legs. 6. The reflector according to claim 5, wherein the separating wall has at least two shorter involute branches as contours. 7. The reflector according to claim 5, wherein a part of or a part of the shorter involute branch is removed from the separation wall. 8. The reflector according to claim 5, wherein the separating wall has a simplified profile as compared to the involute. 9. The separation wall according to claim 5, wherein the contour includes a region near a vertex of a longer involute as a contour.
Reflector as described. 10. A light source wherein the glass sphere has two parallel legs (54, 56) and the reflector has two long sides (53) and two short sides (55). 2. A lighting device (50) comprising a reflector and a light source according to claim 1, characterized in that it comprises a lamp (52) which is a lamp (51).