DE19606179A1 - Outdoor display lettering illumination - Google Patents

Abstract

The illumination for lettering in outdoor advertising displays and the like, in single letters or series, has a strip light source (6) inserted in a shaped body (1) of a transparent material. The emerging light from the strip (6) passes wholly into the body (1) through the side against the light. The shape of the light strip (6) follows the shape of the letter body, or series of letters, wholly or partially. The body (1) is pref. of acrylic glass.

Description

This invention relates to a lighting device according to the Preamble of claim 1. Such lighting devices find especially in scoreboards, displays and the like Chen use.

In known lighting devices of the type mentioned emits a light source spaced from the body, e.g. B. a neon tube, light on the body, which through the Body runs and exits on a light exit surface, which appears illuminated by it. The side faces of the body pers with the exception of the light entry surface and the light output tread are light-absorbing, around a light emerges at a different location than the light exit surface  to prevent che.

Such lighting devices are disadvantageous in that they hold the light source outside the body require and usually only part of that of the light source emitted radiation falls on the body and can be used.

There are also lights integrated into a plastic body diodes have been proposed as lighting devices, whatever but has the disadvantage that for the viewer of the To recognize the light exit surface as point light sources are.

It is the object of the invention to provide a lighting device to create the kind mentioned above, which is a better one Luminous efficiency and homogeneous illumination of the light tread allowed.

This object is achieved according to the invention by a light device tion solved with the features of claim 1. Beneficial Further developments are specified in the subclaims. The Material of the body can be transparent or diffuse ("milky") and depending on the application, if necessary also be colored. As a rule, the band-shaped light swell lying flat either in a groove on the side of the body or on a flat side surface of the body  glued on. You can also, e.g. B. by shedding, in the Kör be integrated by. The light source can with a certain Inclination to be mounted to the emitted light majority to be directed towards a mirrored surface. Training a side surface of the body as a mirror can by Ver reflect the surface using known techniques, e.g. B. by Be vaporize with a reflective material, stick one reflective film or the like can be achieved. There a certain amount when light hits an interface Light component is reflected, but can have a mirror effect also by high-gloss polishing the corresponding surface be enough. This area is expediently used arrange so that most of the light coming from one suitable for the reflection to the light exit surface direction is reflected.

According to the band-shaped light source Light emission more uniform with respect to the direction of the tape, while the surface designed as a mirror is a virtual one Light source forms, so that the light exit surface of egg ner further side and thus is illuminated more evenly. The body can have several surfaces designed as mirrors have, the mirror effect ongoing in the body Concerns light, d. H. light running in the body turns on the mirrored surface is reflected back into the body.

The band-shaped light source only shines on the narrow sides  a small amount of light while the mirror surface due to the directed reflection towards the light exit surface the absorption on light-absorbing surfaces of the body reduced, so that the overall luminous efficiency is improved becomes. Advantageously, the mirror surface deflects Beam of light that comes directly from the light source or from one non-diffusely reflecting surface comes to the light tread.

Advantageously, a wall of the body is e.g. B. by Ver designed as a concave or convex mirror and reflects light coming from the light source or another ren mirror surface comes to the light exit surface, that the radiation so reflected is determined by a certain the curvature and orientation of this wall section covers the defined section of the light exit surface can of course also be the entire light exit surface. The beam cone can both be broken up by the reflection expands as well as narrows.

Additionally or alternatively, the one outlined above can be used Arrangement can be modified so that at least part of the light incident on the curved wall element via a second, preferably flat mirror to the light exit surface is reflected.

The light decoupling on the light exit surface can  can be effected in two ways.

The band-shaped light sources and the inwardly mirrored interfaces of the body can be set up so that the light running in the body incident on the light exit surface at an angle α, which is greater than the angle of total reflection α _T. The light then emerges only at the points of the light exit surface with an irregular surface, because although the angle of incidence is larger on average than the angle of total reflection, the angle of incidence may be locally smaller than the angle of total reflection. Such an irregular surface can be achieved in a known manner by etching, grinding or by applying a light-scattering substance or film.

Alternatively, the light source and the reflective Surfaces should be set up so that they emit te or reflected light at least partially in a win incident on the light exit surface, which is smaller than the angle of total reflection so that it out of the body partially emerges. However, since a certain proportion of light is reflected back into the body, it is before partial, a parallel to the light exit surface to provide a mirrored surface, which, if necessary, too together with other mirrored surfaces of the body, the Guides light back to the light exit surface.  

For certain applications, it can be disadvantageous that the light coming directly from the light source from the Light exit surface emerges. This is especially true when if the band-shaped light source consists of several individual lights sources and the distance from the light source to the Light exit area is too small for the cone of light of the individual light sources overlap at the light exit surface can pen. For such cases, the light source can pass through a suitable orientation or usual beam-limiting Arrangements must be set up in such a way that it works out shone light that without prior reflection to the light exit surface, there at an angle of incidence larger than the angle of total reflection occurs.

The lighting device according to the invention has a massive Body, which in particular also consist of plastic who can be easily shaped and worked. she is therefore easy to manufacture even in complicated shapes.

In particular, it can have the shape of a letter, where the band-shaped light source is attached to the side and runs around the entire letter. Because as material blow or break for the body of the lighting device stes plastic material, e.g. As acrylic glass can be used and the light source can be easily replaced such illuminated letters have a longer lifespan than about the neon tube letters used in outdoor advertising  Ren. Furthermore, a low voltage light source can be used det, which leads to an energy saving compared to lighting letters from neon tubes.

For use as a concentrated light source, e.g. B. for a microscope, the lighting device according to the invention be rotationally symmetrical. By an inclination the light exit surface inwards can be reached that the light emerging from the lighting device on egg a small central area is concentrated.

On the one hand, there are band-shaped light sources Printed circuit boards available on which in SMD technology Light-emitting diodes are applied in close succession. On the other hand but there are also band-shaped light sources, which over ih rer length continuously generate light, e.g. B. the under Tradename Super Neo Neon (SNN) known material of the E-LITE technology, described in U.S. Patent 5,845,752 is written.

Further features and advantages of the invention result from the following detailed description, in which on the attached drawings.

Fig. 1 shows a cross-sectional view of a first imple mentation form of the invention.

Fig. 2 shows a cross-sectional view of a second imple mentation of the invention,

Fig. 3 shows a cross-sectional view of a third imple mentation of the invention,

FIGS. 4a and 4b show a sectional view of a portion of the beam path of the third embodiment of the invention He,

Fig. 5 shows a luminous letters, which is formed according to the first to third embodiments of the invention being,

Fig. 6 shows a rotationally symmetrical light-emitting device according to the invention with a central light exit,

Fig. 7 shows in cross section a first Ausführungsvarian te of the lighting device shown in FIG. 6,

Fig. 8 shows in cross section a second Ausführungsva riante of the lighting device shown in FIG. 6,

Fig. 9 shows in cross section a third Ausführungsva riante of the lighting device shown in FIG. 6,

Fig. 10 shows in cross section a fourth Ausführungsva riante of the lighting device shown in FIG. 6,

Fig. 11 shows in cross section a fifth Ausführungsva riante of the lighting device shown in FIG. 6,

Fig. 12 shows a rotationally symmetrical light-emitting device according to the invention, which can be ver turns as a signal device,

FIG. 13a-13j show various configurations of a groove for accommodating the band-shaped light source,

FIG. 14a-14d show various arrangements of a belt-shaped light source in a groove of the body.

In the following description, the same or equivalent elements of the lighting device according to the invention tion with the same reference numerals. Mirrored Areas are parallel to one by a dashed line solid line indicated.

In Fig. 1, a first embodiment of the inventive lighting device is shown in cross section.

The lighting device consists essentially of a Kör by 1 of a transparent material, for. B. acrylic glass, which can be transparent or cloudy. The body has two parallel parallel boundary surfaces 2 and 3 , which are connected by side walls 4 . In the side walls there is a groove 5 , z. B. formed by milling, in which a band-shaped light source 6 extends. This light source can e.g. B. a ribbon-shaped printed circuit board, which is densely populated in SMD technology with light-emitting diodes, or a ribbon of the material Super Neo Neon (SNN) and preferably has on the side of the body connections for a power supply (not shown). The groove 5 and the band-shaped light source 6 extend in the direction perpendicular to the cutting plane substantially over the entire side of the body. By inserting into the groove it is achieved that essentially the entire usable light output of the band-shaped light source 6 enters the body 1 . If the lateral radiation of the light source 6 is low, for example in the case of a very thin strip of SNN, the groove 5 can also be dispensed with and the strip can be glued directly to the side wall 4 of the body 1 .

The surface 2 forms the light exit surface of the body and can have a roughened section 2 '. The light exit surface 2 opposing surface 3 is mirrored to the inside, so that they reflect light that propagates in the body 1 to the light exit face. 2

The light emitted by the light source 6 is partially incident on the mirrored surface 3 and partially on the light exit surface 2 . The light incident on the light exit surface 2 occurs with the intensity insofar as the angle of incidence a is greater than the angle of the total reflection α _T

I _T = I _O · sin² (α - α _T )

out and becomes with an intensity

I _R = I _O · cos² (α - α _T )

reflected, where I _{O is} the intensity of the incident light. Light that is incident on the light exit surface with an angle of incidence α greater than the angle of total reflection α _T is completely reflected.

The light reflected at the light exit surface 2 runs to the mirrored surface 3 , which, like the light directly incident on it from the light source 6, reflects it back to the light exit surface 2 .

When reflecting between parallel surfaces, the angle of incidence on a surface remains the same for successive reflections. In order to achieve a light emission of that light portion that initially falls at an angle greater than the angle of total reflection on the light exit surface 2 , in a modification of the embodiment shown in FIG. 1, the mirrored surface 3 can be inclined towards the light exit surface , so that the angle of incidence on the light exit surface 2 changes with repeated reflections. A light emission can also be achieved by a roughened section as shown in Fig. 1 under 2 ', in which the orientation of the upper surface varies statistically, so that light with respect to the central orientation of the light exit surface 2 an angle of incidence greater than the angle of total reflection, locally finds an angle of incidence smaller than the angle of total reflection. The same effect can be achieved by a diffusely scattering coating of the light exit surface 2 or by using a diffusely scattering material as for the body 1 .

In the embodiment of FIG. 1 with parallel surfaces 2 and 3 , a beam-limiting device, for. B. an aperture may be provided, which causes the angle of incidence of the light emanating from the light source 6 on the light exit surface 2 and on the reflecting surface 3 is greater than the angle of the total reflection. In this case, light can only emerge in the roughened section 2 ', while the light is totally reflected in the remaining area of the light exit surface 2 .

In the modification of the embodiment of FIG. 1 shown in FIG. 2, in addition to the surface 3, the side walls 14 a and 14 b are also mirrored and with respect to the light exit surface 2 or the reflecting surface 3 is inclined. With a suitable choice of the angle of the Seitenflä surfaces 14 a, 14 b to the normal to the light exit face 2 or the reflecting surface 3, β or γ falls light which is initially at an angle greater than the angle of total reflection on the light exit face 2 occurs after one or more reflections on one of the sides 14 a, 14 b at an angle on the light exit surface 2 that is smaller than the angle of the total reflection. Since mirrored walls 14 a, 14 b are provided on both sides of the body, the light can run several times around in the body, the angle of incidence on the light exit surface being different with a corresponding choice of the angles β, γ in each cycle.

For an exclusive light coupling on uneven sections from the light exit surface 2 , as described above with reference to Fig. 1, the angle between the side walls 14 a and 14 b is chosen to be 90 °, so that a light beam after reflection on both mirrors parallel goes back to its original direction. Further, the angle β greater ge selected as the angle of total reflection, so that on the surface 14 a reflected light always at an angle greater than the angle of total reflection is incident on the light exit face. 2 Finally, the light source 6 is arranged so that the mirrored walls 14 a and 14 b act as an aperture, which prevents the direct incidence of light on the light exit surface at an angle smaller than the angle of the total reflection. In this embodiment, the surface 3 need not be mirrored, provided that it is parallel to the light exit surface 2 , since the light is incident on this surface with an angle of incidence greater than the angle of total reflection.

In the illustrated in Fig. 3 modification of the execution of the Fig form. 1 are again the light exit face 2 opposite surface 3 and the side walls 24 a, 24 b mirror. However, the side walls have in the Kantenbe rich arranged, formed as a dispersive mirror wall portions 25 a and 25 b, which have the task to reflect on the edge portions of light incident directly on the light exit face 2 or the reflecting surface 3 and over a specific surface area to distribute. A corresponding beam path is shown as an example in FIGS. 4 a and 4 b.

FIG. 4a illustrates the operation of the mirror-coated wall portion 25 a. The incident from the light source 6 on the wall section 25 a light bundle S1 is reflected by the wall section 25 a and expanded, so that it covers practically the entire light exit surface 2 . Similarly, light reflected from the surface 3 at a large angle of reflection is reflected via the wall element 25 a to the light exit surface 2 . The degree of expansion of the beam S 1 depends on the degree of curvature of the wall element 25 a. With a correspondingly large radius of curvature R₁ and corresponding position of the center of the circle of curvature P₁ for the area of incidence, the beam S₁ detects only part of the light exit surface, which can be advantageous if certain areas of the light exit surface are to be illuminated more intensely.

The operation of the mirrored wall section 25 b is shown schematically in Fig. 4b. The light bundle S2 coming from the light source is reflected by the wall element 25 b, so that it is widened and essentially covers the entire reflecting surface 3 . The surface 3 then reflects part of this light to the light exit surface. The radius of curvature R2 and the center of the corresponding circle of curvature P2 can also be chosen such that the bundle S2 falls into a section of the surface 3 in which it is completely reflected to the light exit surface 2 . The wall element 25 b also reflects at a large angle at the light exit surface 2 re reflected light to the surface 3rd

In a symmetrical structure as shown in Fig. 3, the four mirrored sections 25 a, 25 b are preferably circularly curved and have the same radii of curvature.

In the embodiments of the lighting device according to the invention shown in FIGS . 1 to 4, two band-shaped light sources are in each case arranged opposite one another. Alternatively, however, you can also use only one light source on one of the two sides and mirror the opposite side wall, so that a virtual light source is generated on this side.

In Fig. 5, a lighting device according to the invention is shown in the form of a light letter (W), which leads out according to one of the embodiments described above. The views of FIGS. 1 to 4 correspond to a section perpendicular to the dashed line of the letter, for. B. along the line II indicated in Fig. 5. The light exit surface 2 is covered with a diffusely scattering color film. As described above, the band-shaped light source 6 is attached to the side surface of the letter and preferably runs around the entire contour of the letter. Also preferably on the side or on the back of the letter, connections for the light source (not shown) are provided in the usual way, with which the light source can be connected to a suitable power source. The letter advantageously consists of an unbreakable plastic material, e.g. B. acrylic, and has a low voltage light source, e.g. B. LEDs or SNN on.

Fig. 6 is a plan view of a further embodiment of the lighting device according to the invention, which is intended for a con-centered light emission in a small area, as is required for microscopes. A sectional view along the line II-II is shown in FIG. 7. In this embodiment, the body 1 is formed rotationally symmetrical. In the upper surface 34 of the body there is an annular groove 35 , in which a band-shaped light source 36 is arranged, which has suitable connections for a power supply. The band-shaped light source 36 can be provided continuously in the groove 35 , so that it is essentially a ring bil det, or, as shown in Fig. 6, sectionally in segments ( 36 a- 36 d) may be provided. The materials described for the preceding embodiments can be used as the light source. Radially inward, an inclined light exit surface 32 adjoins the upper surface 34 , as can best be seen in the sectional view in FIG. 7, and adjoins at its lower end the underside 37 parallel to the upper surface 34 . In the center of the body 1 there is accordingly a continuous frustoconical recess. The upper surface 34 , the underside 37 and the side walls 33 are mirrored inwards so that they reflect light from the inside of the body 1 back onto them in the body. The principles of the embodiments described above with reference to FIGS. 1 to 4 can be applied to the design of the mirrored surfaces.

In general, in this rotationally symmetrical embodiment, the band-shaped light source 35 can also be attached to a side wall of the body 1 , as is shown in FIG. 8. It can be waived on a flat surface 34 .

Different variants of the lighting device according to FIG. 6 are described below by way of example with reference to FIGS . 8 to 11.

Referring to FIG. 8, a light source 36 adjacent the ver-mirrored wall portion 44 b is provided, the light exit surface 32 or the wall on which the light source 36 is mounted with respect to, has an obtuse angle. This wall section reflects light incident thereon to the reflecting surface 37 , which in turn directs the light to the light exit surface 32 . Furthermore, a second mirrored flat wall element 44 a is provided, which is inclined with respect to the surface 44 a. As with the guide die from Fig. 2, the angle between the faces 44 a and 44 b be 90 °.

Instead of the flat, mirrored wall section of FIG. 8, a curved wall section 54 b can also be provided, which directs light incident thereon to the reflecting surface 37 (cf. FIG. 9). Furthermore, a curved mirrored wall section 54 a can be provided, which reflects a light beam that falls directly on it from the light source 36 toward the light exit surface 32 , this light bundle being able to cover the entire light exit surface 32 ( FIG. 9, FIG. 10).

The reflected from the curved wall elements 54 a beam expand after emerging from the light exit surface 32 . A maximum light intensity is achieved where the beams that emerge from radially opposite surface sections 32 overlap. By a suitable choice of the orientation and the radius of curvature of the wall sections 54 a, this overlap pungsbereich can be shifted in the axial direction, the larger it is the further it is from the bottom 34 of the body pers.

Another variant of the lighting device according to FIG. 6 is shown in FIG. 11. In this embodiment, body 1 has a curved underside 63 that extends downward from top surface 34 . The light exit surface 32 adjoins the upper surface 34 in which the light source 36 is arranged, and it extends obliquely downwards from this to the lower end of the underside 63 . The upper surface 34 and the underside 63 are mirrored inwards, the mirrored surface 63 acting as a collecting mirror, which bundles the light incident on it in the body 1 and reflects it to the light exit surface 32 . The focal point of the mirror 63 lies outside the body, so that the beam cones emerging from the two opposite surface sections 32 taper. The maximum Lichtinten intensity results in the overlap area of the two beam cones, this overlap area can be rich by a corre sponding design of the curved surface 63 in a room in which the beam cone has only a small diameter, which is about to be illuminated Object, e.g. B. corresponds to a microscope.

FIG. 12 shows an embodiment of the lighting device according to the invention as a signal lamp. Here, the body 1 is substantially circular cone-shaped and has at its blunt end a transparent, possibly colored lens 72 , while at the tip end in a recess a pulse light source 71 , for. B. a light emitting diode is provided for flashing signals. To emit continuous light, a band-shaped light source 76 is arranged in a groove 75 , which runs along the circumference of the body 1 and preferably the diffusing screen 72 is adjacent, as described above, which emits light directly into the body 1 . The outer surfaces of the body 1 are mirrored inwards so that they reflect light propagating in the body, which is incident on them, back into the body. The body 1 can also have a shape deviating from the circular cone shape and can be designed in particular in the radial cross section as shown in FIGS. 1 to 4. The pulse light source can optionally be omitted. As in the previously described embodiments, the band-shaped light source, e.g. B. SNN or a Leiterstrei fen with light emitting diodes, which are mounted in SMD technology.

As above with the various embodiments has been explained, the ver provided on the body reflected surface elements varied in a variety of ways will. However, the lighting device according to the invention can can also be modified in other respects.

FIGS. 13a-13j diagrammatically illustrate a series of ways in which the source for receiving the strip-shaped light provided groove 5 can be designed. So z. B., as shown in FIGS. 13a and 13b, in which the light source is not shown for the sake of simplicity, the groove may be inclined in order to make the light emitted by the light source stronger towards the light exit surface 2 ( FIG. 13b) or to a mirrored surface, such as the side surface 4 in Fig. 13a. In particular, in this way the light emitted by the light source can be applied to a wall section of the body which is formed as a collecting or diverging mirror. Fig. 13c shows a partial view of a corresponding body 1 (without light source) having a scattering out as mirror formed wall portion 66 and Fig. 13d shows a entspre sponding view of a body 1, with a designed as a collection mirror portion 67. In the groove 5, when light emitted from the belt-shaped light source substantially only in a direction of a side surface 5 may be mirrored a, in order to prevent light leakage from the body into the groove, as shown in Fig. 13a.

Fig. 13e shows a partial view of a groove 5 , in which a side wall 5 a is mirrored outwards and inwards, so that light emitted by the light source, which is incident on the surface 5 a, is reflected to the opposite surface 5 b. In Fig. 13f such a double mirrored surface 5 a is shown in connection with an asymmetrical groove 5 ge.

The groove can also be formed step-shaped (see. Fig. 13g and Fig. 13h). In such a step-like configuration, the band-shaped light source 6 can be arranged parallel to the light exit surface 2 ( FIG. 13h) or parallel to a side surface 4 ( FIG. 13g). The groove 5 may be formed (Fig. 13i and FIG. 13j) in the reflecting surface 3. In order to utilize light radiated into the space between the groove and the side wall 4 , the side wall 4 can be beveled as shown in FIG. 13j.

Figs. 14a to 14d show different ways of arranging the belt-shaped light source 6 in the groove 5 in view of a divisional applications. The light source 6 can be arranged parallel to the bottom 5 ₃ of the groove ( Fig. 14a) or parallel to a side surface 5 ₁ of the groove ( Fig. 14b). Furthermore, two parallel band-shaped light sources 6 a and 6 b can each be arranged parallel to the side walls 5 ₁ and 5 ₁ of the groove 5 ( Fig. 14c). Finally, parallel to all three sides of the groove, 5 ₁- 5 ₃, band-shaped light sources 6 a- 6 c can be arranged ( Fig. 14d).

The in the above description, the claims as well Features of the invention disclosed in the drawing can thus probably individually as well as in any combination for the Ver implementation of the invention in its various embodiments forms are essential.

Claims (18)

1. lighting device with a body ( 1 ) made of a transparent material, one or more light sources which radiate light into the body, and a light exit surface ( 2 ) on one side of the body, via which light radiated into the body from the body emerges, characterized in that a band-shaped light source ( 6 ) is attached to the body in such a way that the light which emerges from a side of the band-shaped light source ( 6 ) facing the body essentially completely enters the body ( 1 ), and that a side surface of the body ( 3 ; 14 b) is at least partially formed as a mirror for light running in the body, which at least partially reflects light incident on it to the light exit surface ( 2 ). 2. Illuminating device according to claim 1, characterized in that a wall section ( 25 a; 54 a) of the body ( 1 ) is designed as a curved mirror, the light incident on it from the interior of the body at least partially to the light exit surface ( 2nd ; 32 ) reflects. 3. Illuminating device according to claim 2, characterized in that the wall section designed as a curved mirror ( 63 ) is designed as a collecting mirror and adjoins the light exit surface ( 32 ). 4. Illuminating device according to claim 2 or 3, characterized in that the wall section formed as a curved mirror ( 25 a, 54 a) of a side surface formed as a mirror ( 3 ; 37 ) of the body is adjacent, which at least part of the it reflects incident light from the body ( 1 ) to the light exit surface. 5. Illuminating device according to one of claims 1 to 4, characterized by a reflective arrangement with a first wall surface formed as a mirror of the body ( 25 b), the light incident on it from the inside of the body at least partially formed to a second as a mirror Reflected wall surface ( 3 ) of the body, which at least partially reflects incident light to the light exit surface ( 2 ). 6. Illuminating device according to claim 5, characterized in that the first wall surface ( 25 b) formed as a mirror of the reflecting arrangement is curved. 7. Illuminating device according to claim 5 or 6, characterized in that the first wall surface ( 25 b) formed as a mirror of the reflecting arrangement adjoins the light-emitting surface ( 2 ). 8. Illuminating device according to one of claims 1 to 7, characterized by a curved wall portion ( 25 a, 25 b) formed as a mirror in an edge region of the body. 9. Illuminating device according to one of claims 1 to 8, characterized in that the light exit surface ( 2 ) is opposed to a substantially parallel, surface designed as a mirror ( 3 ) of the body ( 1 ). 10. Illuminating device according to claim 9, characterized by two flat surfaces designed as mirrors ( 14 a, 14 b) for reflecting light running in the body, which are inclined at 90 ° to one another, one of these two surfaces ( 14 b) adjoined to the light exit surface substantially parallel, configured as a mirror surface (3) and with respect to the ser surface (3) is inclined. 11. Illuminating device according to one of claims 1 to 10, characterized in that the band-shaped light source ( 6 ) extends substantially in one direction parallel to the light exit surface. 12. Lighting device according to one of claims 1 to 11, characterized in that the band-shaped light source ( 6 ) continuously emits light with respect to its longitudinal direction. 13. Illuminating device according to one of claims 1 to 11, characterized in that the band-shaped light source ( 6 ) is constructed from spaced individual light sources. 14. Illuminating device according to one of claims 1 to 13, characterized in that the band-shaped light source ( 6 ) is arranged such that the light incident directly from it onto the light exit surface ( 2 ) has an angle of incidence (α) which is greater than the angle of total reflection. 15. Illuminating device according to claim 14, characterized in that the surfaces formed as a mirror of the body ( 1 ) are set up in such a way that the surface they reflect to the light exit surface ( 2 ) reflects light at the light exit surface at an angle of incidence which is greater than the angle is the total reflection, and the light exit surface ( 2 ) has a section with an irregular surface. 16. Illuminating device according to one of claims 1 to 15, characterized in that the body ( 1 ) has a substantially rotationally symmetrical shape and the light exit surface ( 72 ) is substantially perpendicular to the axis of symmetry. 17. Lighting device according to one of claims 1 to 14, characterized by a rotationally symmetrical conical light exit surface ( 32 ) which tapers towards the inside of the body ( 1 ). 18. Lighting device according to one of claims 1 to 15, characterized characterized as being in the form of a character or a sequence of characters.