Classifications

• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F13/00—Illuminated signs; Luminous advertising
  • G09F13/04—Signs, boards or panels, illuminated from behind the insignia

Definitions

• the invention relates to a light diffuser for use on an elongated light source, preferably a fluorescent tube, in order to achieve the most uniform possible radiation distribution over a surface lying in front of the light source, with a light-scattering plastic film which has a light transmission profile adapted to the light source.
• Light diffusers of the type mentioned above are frequently used in display cases, for example advertising display boxes, in order to achieve uniform illumination of the area to be irradiated.
• the display cases are illuminated from the rear by a certain number of fluorescent tubes evenly distributed over the area to be illuminated.
• a light diffuser consisting of a translucent plastic film is placed between the light sources and the surface to be illuminated.
• Such a light diffuser has approximately the dimensions of the surface to be illuminated and can be attached to it from behind, for example by gluing.
• the light diffuser has an adapted to the light source distribution
• Light transmission profile such that at locations on the surface that would be strongly ⁇ illuminated without the use of a light diffuser, a correspondingly high
• Radiation is weakened by the diffuser and areas of low illumination are only slightly attenuated. Overall, this makes one uniform illumination of the area is achieved.
• a disadvantage of the plastic films used hitherto is that they have to be precisely adapted both to the number of light sources used in such a display case and to the size of the display case.
• the present invention is therefore based on the object of creating the possibility of building surface lighting of this type without having to use foils which are specially adapted to the spacing of the light sources and dimensions of the display case.
• the plastic film is designed as a strip that ends at its two ends in a fastening shoe, which is adapted in its shape to the light source to be used such that the strip is directly at the light source with the required Can fix distance to the light source.
• the light diffuser according to the invention has the advantage that it can be attached directly to a light source and is therefore no longer tied to a specific light source configuration or dimension of the surface to be illuminated. Rather, when using multiple light sources, it is sufficient to simply provide each light source with such a strip in order to achieve uniform illumination of the entire surface.
• the light diffuser according to the invention preferably has
• Fastening shoes which are designed as tabs each with a circular opening, the size of the openings being adapted to the light source to be used such that the ends of the light source are form-fitting can be inserted into the tabs.
• Such fastening shoes are particularly easy to manufacture and nevertheless lead to a sufficient hold of the strip on the light source.
• the light diffuser can be moved or rotated on the light source as desired, which is advantageous for mounting the light diffuser or for fine-tuning the light distribution.
• the edge of the opening has radially extending incisions.
• the resulting slats which point towards the center of the opening, allow the opening of the fastening shoe to be variably adapted to the diameter of the light source used.
• the advantage of this embodiment is that the light diffuser can thereby be used for light sources with different diameters.
• the strip preferably has a fold edge in parallel and at a certain distance from the edges running in the longitudinal direction, along which the edge strips formed in this way are bent at a certain angle, preferably by about 45 °, from the plane of the strip to the same sides .
• angled edge strips allow further influencing of the radiation field provided by the light source. If the two edge regions are bent in the direction of the light source, the radiation field will be narrower than, for example, in the case in which the edge regions are bent away from the light source. By kinking the edge areas by certain angles, the distances between the neighboring light sources can be matched in particular.
• the light transmission profile of the strip is preferably achieved by printing on a grid with a correspondingly distributed grid density. This means that any light transmission profiles can be achieved particularly easily and inexpensively.
• the strip is cut into a sawtooth or sinusoidal shape over the entire length of the longitudinal edges.
• Such a configuration can have a further influence on the resulting illumination. If the edges are strongly incised, more light reaches the edge areas of the surface to be illuminated by a light source than is the case with edges that are not or only slightly incised. This in turn can also influence the area illuminated by a light source or can be coordinated with the distances of the light source from neighboring light sources.
• a tongue is cut out and unfolded from the strip near the fastening shoes, such that the light passing through the opening released by the tongue from the tongue in the direction of the fastening shoe or in the direction of the parts of the surface to be illuminated is in close to the ends of the elongated light source is deflected. Since the parts of the surface to be illuminated, which are located near the ends of the light source, are illuminated less strongly than the central regions of the surface, in this special embodiment light can additionally pass through the openings exposed by the tongues, which through the tongues projecting at a certain angle Direction of the mounting shoes or the end of the light sources is deflected. This leads to a more even illumination of the edge areas.
• the tongue is preferably trapezoidal, the wider base being attached to the strip.
• the trapezoidal shape of the tongue has proven to be particularly advantageous.
• At least one predetermined bending line is provided between the fastening shoe and the strip.
• the surface of the fastening shoe, which has the opening, can be bent approximately at a right angle to this predetermined bending line, so that the light source can be pushed through the opening and runs parallel to the strip. Due to the position of the predetermined folding line, the distance of the strip from the light source can be determined in a particularly simple manner.
• the predetermined bending line is preferably formed by opposite V-shaped incisions.
• the resulting tapering of the light diffuser makes it easier to bend the light diffuser.
• Fig. 1 is a pattern of the preferred
• Embodiment of the light diffuser according to the invention as well as two tables with preferred dimension ranges therefor, 2 examples of the course of the light transmission profile,
• Fig. 3 is a partial perspective view of the preferred embodiment.
• Fig. 1 shows an embodiment of a light diffuser according to the invention for use on commercially available fluorescent tubes.
• the light diffuser 1 is manufactured in the form of a strip 2, which ends in a fastening shoe 3 at both ends.
• the light diffuser consists of a single part of plastic film.
• the length E of the strip 2 corresponds to the dimensions of commercially available fluorescent tubes and is in the range between 10 and 250 cm.
• the plastic film is designed so that it scatters incident light. If necessary, it can also be colored. The color is preferably white.
• the width of the strip is between 10 and 150 mm, but preferably 40 mm.
• the mounting shoes 3 are designed as tabs, each having an opening 4 corresponding to the diameter of the fluorescent tube used.
• this diameter is between 0.5 and 4 cm, but preferably about 2.5 cm.
• the tabs 3 for fastening the strip 2 are angled at right angles to the latter, so that the fluorescent tube can be pushed through the openings of the tabs.
• the kinking takes place around the predetermined folding edges 8, which are predetermined by the incisions 9. This will keep the strip 2 parallel and at a certain distance from the fluorescent tube on the two Ends of the fluorescent tube reached.
• the opening 4 of the fastening shoe 3 can also be provided with radially running incisions.
• the resulting louvres are pushed outwards to a greater or lesser extent depending on the diameter of the light source used and, thanks to their elasticity, enable the strip to be held on the fluorescent tube.
• the strip 2 held by the fastening shoes 3 parallel to the fluorescent tube and between it and a surface to be illuminated has a light transmission profile that runs symmetrically to its longitudinal axis.
• the profile can preferably have the light transmission profiles shown in FIG. 2.
• the bell-shaped profile c is particularly preferred. Common to all profiles is that the light is most strongly attenuated in the middle of the strip and least diminished at the edge of the strip.
• the profiles shown thus represent absorption profiles. As can be seen in FIGS.
• the preferred light diffuser has prefabricated folded edges 5, by means of which edge regions 6 that can be bent are defined. If these edge regions 6 are bent in the direction of the light source, the radiation field striking the surface will be narrower than in the opposite case if the edge regions 6 are angled away from the light source. Since the number of fluorescent tubes lying next to one another or the spacing between them can be different in the display cases mentioned at the beginning, a variable adaptation to the size of the surface to be illuminated by each light source is possible by clicking on the edge regions 6.
• the width of the edge strips G is, as in the table in FIG. 1 indicated, between 3 and 33 mm, but preferably with a 4 cm wide strip at about 1 cm each.
• FIGS. 1 and 3 shows how the edge regions 6 are bent around the fold edges 5 in the direction of the light source, not shown.
• the angle set is approximately 45 °.
• FIGS. 1 and 3 shows the area close to the fixing shoes trapezoidal tongues 7, which are connected with its broader base with the strip and be folded so may that more light passes in the direction of the edge regions of the surface to be illuminated.
• the light passing through is deflected by the tongues 7, which are opened by a certain angle, in the direction of the fastening shoes or the edge regions of the surface to be illuminated, in order to additionally illuminate the poorly illuminated edge regions. Additional further dimensional ranges are entered in the tables in FIG. 1.
• All of the kink lines shown in FIG. 1 can already be placed individually during manufacture or else by the user himself.
• the width and the angle of the edge areas can be defined by the user himself by varying the crease line 5.
• the intermediate area between the strip and the fastening shoe can be made wider, so that the kink can be placed anywhere over a greater length and thus greater flexibility with regard to the distance of the strip from the fluorescent tube is achieved.
• several parallel ones can run on the intermediate area mentioned Desired folding lines 8 are provided, under which the user can choose the most suitable one.
• the user of the light diffuser will place a light diffuser with a suitable profile, fastening shoe and length on each fluorescent tube, and fine-tune to neighboring fluorescent tubes by means of the foldable edge area. Since the strip can be produced extremely inexpensively, it is also conceivable that the user has a large assortment of different types of strips, of which he can find out the most suitable by briefly trying them out. With some practice, the user can use the light diffuser according to the invention to implement the desired surface illumination for a certain number of light sources without having to produce their own light diffuser in the case of different sizes of the surface to be illuminated or a different number of available light sources.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Illuminated Signs And Luminous Advertising (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6423696

Family Applications (1)

Country Status (2)

Families Citing this family (4)

Citations (4)

Family Cites Families (1)

• 1991
  • 1991-01-25 DE DE19914102199 patent/DE4102199A1/de active Granted
• 1992
  • 1992-01-27 WO PCT/DE1992/000046 patent/WO1992013330A1/de unknown

Patent Citations (4)

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