Light box and strip-shaped profile for use in it

Abstract

 A light box comprises a, preferably lightproof, housing (1) with a rear wall (2) and two side walls (3) with a picture carrier (4) placed in between. The side walls (3) each have an end (31) which extends towards a middle plane perpendicular (8) of the rear wall (2). To facilitate exchange of the picture carrier (4), a profile (9) is placed between picture carrier (4) and the above-mentioned end (31) of each of the side walls (3). The profile comprises a part (91) which has a longitudinal groove (92) placing an edge of the picture carrier (4) and, in addition, attachment devices to grasp the end (31) of the relevant side wall (3), thus fixing the picture carrier (4) in the housing (1).

Description

[0001] The present invention relates to a light box including a, preferably lightproof, housing with a rear wall and two side walls which extend from the rear wall holding a transparant picture carrier, with a light source being provided in the housing between the rear wall and the picture carrier.

[0002] This light box, also called a diapositive box, can be used for signposting in buildings, as an information board, or for commercial purposes; in the latter case, the picture carrier displays a certain commercial message. The size of the light box can be chosen freely, and ranges in practice from, for example, A4 size to A0 size or even larger. In all these cases, the light source inside the light box makes the picture carrier more eye-catching. Particularly when the light box is used for commercial purposes, it is often desirable that the picture carrier is regularly replaced by a more updated version. Preferably, the light box includes a device which enables replacing the picture carriers.

[0003] A familiar light box of the type as referred to in the opening lines includes a case-shaped housing in which a light source has been placed and of which the side walls have been provided with a guiding profile in which the picture carrier can be pushed. In these cases, the picture carrier is usually flanked by a white glass at the back, being the side which is turned towards the light source, and by a window glass at the front. In order to enable the exchange of picture carriers the cover of the housing includes a hinging part which makes the picture carrier accessible and can be removed from the guidance.

[0004] Especially in case of rather large-sized light boxes or if light boxes have been placed (high) on a wall, the use of this familiar device for exchanging picture carriers turns out to be laborious, if not impossible, in practice. In case of picture carriers which are taller than 1.20 metres or in case of light boxes which have been placed high on a wall, picture carriers will, in case of an average ceiling height of 2.40 metres, of course bump into the ceiling before they have been completely lifted out of the light box.

[0005] In any case, additional equipment, among others a step ladder, is often required to get the work done. For these reasons, the replacing of picture carriers, however desirable, is sometimes refrained from in practice.

[0006] The present invention aims at providing a light box of the type as referred to in the opening lines which avoids this difficulty, because the picture carrier inside can be replaced much more easily.

[0007] To this end, the light box of the type as referred to in the opening lines according to the invention is characterised in that the side walls extend at their ends in a direction of an imaginary middle plane perpendicular of the rear wall and that a detachable strip-shaped profile is provided between the picture carrier and both side walls with a longitudinal groove for the edge of a picture carrier to fit in it and with attachment means to grasp the end of the respective side wall. In case of a light box, according to the invention the picture carrier can be removed easily by exerting pressure on the picture carrier from the side via both profiles in the direction of the above-mentioned middle plane perpendicular which will flatten the picture carrier and which will cause the means of attachment to release the above-mentioned ridge. Now the picture carrier can be removed from the light box in order to be replaced. The new picture carrier can be placed in an analogous way. Because the picture carrier is removed from the light box via the front side, the above-mentioned difficulties associated with larger-sized light boxes or light boxes placed directly under the ceiling are avoided.

[0008] In a special version the attachment means comprise a longitudinal strip which is an integrated part of the profile and which extends from the longitudinal groove beyond the edge of the side wall. In this case, the longitudinal strip grasps behind the end of the relevant side wall which is directed to the inside, fastening the picture carrier in the light box.

[0009] Preferably, the profile according to the invention comprises a groove which narrows at its bottom. In the wedge which is subsequently formed picture carriers can always be kept clamped fit, within certain limits that is, irrespective of their specific thickness.

[0010] Another preferential version of the light box according to the invention features is characterised in that the part of the profile which contains the groove is supported with a longitudinal rib on the end of a side wall, the longitudinal rib being installed at some distance from the bottom of the groove. The longitudinal rib provides some space between the part of the profile in which the edge of the side wall is clamped and the edge of the relevant side wall of the housing which is directed to the inside. Especially, in case of a flat picture carrier the profile can be more easily grasped in order to buckle the picture carrier to the inside subsequently and remove it.

[0011] In order to avoid that light of the light source is allowed to escape via the upper or lower edges of the picture carrier, another special version of the light box according to the invention is characterised in that the housing comprises a bottom and a cover which have both been provided with a rib on the inside which follows almost exactly the contour of the picture carrier and which has been placed between the light source and the picture carrier.

[0012] Furthermore, the invention includes a strip shaped-profile to be applied in this light box which will now be discussed in more detail using an examplary embodiment and an accompanying drawing, in which:

figure 1

shows a cross section of an embodiment of a light box according to the invention.

figure 2

provides a detailed drawing of a smaller part of figure 1;

figure 3

provides a cross section of the light box in a direction transverse to figure 1; and

figure 4

provides a cross section of another embodiment of a light box according to the invention.

[0013] The drawings are purely schematic and have not been drawn to scale. Especially for reasons of clarity, some dimensions are represented extremely large or small.

[0014] The corresponding parts in the figures are to the best possible extent indicated with one and the same reference number.

[0015] The light box of figure 1 includes a, preferably lightproof, housing 1 with a back wall 2 and two side walls 3 which extend from back wall 2 onwards to the front. Between both side walls a picture carrier 4 has been placed forming in this case a package with a white glass 5 which has been placed behind it and a window glass 6 which has been placed in front of it. In the version shown in figure 1; the picture carrier package 4-6 is convex curved. Although glass is mentioned here, it is obvious that suitable synthetic material can be used instead. The picture carrier includes a synthetic film or a paper sheet with the desired imprint, which can be a text, an image, or a combination of this. By means of a light source 7 which is placed between picture carrier 4 and the back wall of this picture carrier 4 is (high)lighted, which makes it considerably more eye-catching.

[0016] In principle, any type of lamp can be used as a light source. However, it is preferable to use a light source, analogous to this example, which includes a number of parallel tubular parts which cover almost the entire width or length of the housing. In this case it is possible, particularly by the intervention of diffusing white glass 5, to realise a smooth and homogeneous light distribution in picture carrier 4. In this example, the light source includes three vertically placed neon tubes 7. Instead, without suffering the loss of homogeneity, single meander-shaped illumination can be used too and, in principle, also a different number of neon tubes can be used.

[0017] In order to be able to replace the picture carriers easily, both side walls 3 have been constructed in such a way that an end 31 extends from there in the direction of the imaginary middle plane perpendicular of back wall 2, this is schematically drawn with a dotted line, and a detachable strip-shaped profile 9 has been placed between picture carrier 4 and end 31 of the relevant side wall 3, which is shown in more detail in figure 2. The profiles 9 cover almost the entire height of picture carrier 4.

[0018] The strip-shaped profile 9 includes part 91 with a longitudinal groove 92 for placing a ridge of the picture carrier 4 in it, in this example in combination with the window and white glass 5, 6. The groove 92 narrows towards its bottom 93, thus clamping the picture carrier package 4-6 free of play at all times, independent of the specific thickness of the package 4-6. Thus, in the light box annoying noise of the picture carrier 4-6 package is avoided. In addition to this, strip-shaped profile 9 is equipped with attachment devices, in this case shaped like a continuing longitudinal strip 94, to grasp end 31 of side wall 3 concerned. Longitudinal strip 94 is an integrated part of profile 9 and extends over the entire length of profile 9. The same goes for longitudinal rib 95 of profile 9 with which part 91 leans with groove 92 on end 31 of the relevant side wall 3. As a result of this design, profile 9 is produced simply by an extrusion process. Therefore, the profile is preferably made of extruded material, for example aluminium, suitable plastics or other extrudable metal.

[0019] Longitudinal rib 95 is attached at a certain distance from bottom 93 of groove 92, and thus offers a space 96 which can be reached by the fingers, and which ensures a better grip on profile 9, which in turn facilitates changing picture carrier package 4-6. In order to change package 4-6, the fingers will enter space 96 at both sides of the light box, while the hand and thumb rest against the front wall of package 4-6. By exerting slight pressure towards the middle plane perpendicular, the curvature radius of the picture carrier package becomes smaller, and consequently profile 9 releases end 31 on both sides of side walls 3. Subsequently, the entire package can be removed and the picture carrier may be changed, if so desired, after which picture carrier package 4-6 may be put back similarly. Since the package is taken out from the front side out of the light box, all this is also possible with large-size light boxes with heights exceeding 1.20 metres and with light boxes suspended directly beneath a ceiling.

[0020] In addition, the housing includes a bottom 10 and a cover 12 that are both internally provided with a rib 11 respectively 13, which follows almost exactly the contour of the picture carrier package and is attached between picture carrier 4 and light source 7, see figure 3. This way, ribs 11 and 13 avoid the light of light source 7 to escape across the upper or lower ridge of the picture carrier package, which, as required, is to some extent moveable.

[0021] Figure 4 shows another embodiment of the light box according to the present invention in which the picture carrier package 4-6 is placed concave curved between the side walls 3 of the housing 1. The placement of the picture carrier 4 in the housing 1 and the exchange thereof are performed in a similar manner as in the version as shown in figure 1. In the version according to figure 4 the back wall 2 is not fully straight, but formed in an angle near the ends. By this the light distribution of the light sources 7 is optimalised.

[0022] Although in the above paragraphs the invention has been explained on the basis of one example of implementation only, it is obvious that the invention is not at all restricted to this example. On the contrary, within the framework of the invention there are many possible varieties and forms. Thus the invention is not only applicable for light boxes with a curved picture carrier, but it is just as much beneficial for light boxes with a flat picture carrier. In the latter case, the space which is created as by the longitudinal rib helps to bend the flat picture carrier slightly inward in order to remove it as described above.

[0023] Instead of a continuing strip, it is also possible to apply other attachment devices to fasten the profile to the side ends, by using, for example, one or more separate clamping devices or clamping lugs which clamp the ends.

[0024] In general, the invention thus provides light boxes with a transparent picture carrier, which can be removed and attached in a simple way.

Claims

1. Light box including a, preferably lightproof, housing with a rear wall and two side walls which extend from the rear walls holding a transparent picture carrier, with a light source being provided in the housing between the rear wall and the picture carrier, characterised in that the side walls extend at their ends in a direction of an imaginary middle plane perpendicular of the rear wall, and that a detachable strip-shaped profile is provided between the picture carrier and each of the side walls with a longitudinal groove for the edge of the picture carrier to fit in it and with attachment means to grasp the end of the relevant side wall.

2. Light box in accordance with claim 1, characterised in that the attachment means comprise a longitudinal strip which is an integrated part of the profile and which extends from the longitudinal groove beyond the edge of the side wall.

3. Light box in accordance with claim 1 or 2, characterised in that the profile comprises a groove which narrows at its bottom.

4. Light box in accordance with claim 1, 2 or 3, characterised in that the part of the profile which contains the groove is supported with a longitudinal rib by the side wall end, the longitudinal rib being provided at some distance from the bottom of the groove.

5. Light box in accordance with one of the above-mentioned claims, characterised in that the profile being made of extruded metal or plastic.

6. Light box in accordance with one of the above-mentioned claims, characterised in that the housing comprises a bottom and a cover that are both internally provided with a rib which follows almost exactly the contour of the picture carrier and is placed between the light source and the picture carrier.

7. Strip-shaped profile applicable in the light box in accordance with one of the above-mentioned claims.

Drawing