There exist in the prior art several display devices wherein the panel containing a message is a moving panel. Almost all these devices are designed such that the panel moves on one single plane. In other devices, there are problems associated with driving the panel, which does not move in a uniform manner or does nor move at all, or that cause situations of friction and wear that render the apparatuses impractical to be used.

The aim of the present invention is to propose a panel driving mechanism for a public message display board which eliminates all the problems associated with the prior art, that is, it allows the panel containing the message, either an advertisement, information, or other message, to move over a curved profile support, thereby becoming much more attractive from the point of view of the display itself of the message, without any problem of friction of the panel on the rotating support element thereof. Furthermore, since one end of the panel is directly connected to the other end, the mechanism allows the same to"roll"without any staggering or discontinuity, rendering the display of the message both continuous and smooth.

To this end, the panel driving mechanism for a public message display board that constitutes the object of the present invention comprises an

electromechanical system comprised of a metal cowling with a curved front shape which functions as a securing structure for the mechanical drive system and also for the back lighting electric installation of the display board and a support over which slides a panel with a message intended to be read.

This electromechanical system is comprised by a low rotation reduction drive formed by a direct current electric motor, additionally mechanically reduced by means of pulleys and belts that transmit rotation to three panel driving shafts, whereof one shaft, designated as rotation transmission main shaft, is provided with a set of sleeves made of an appropriate anti-skidding material, particularly silicone, enabling the adherence and the movement of the panel bearing the image between the other two shafts that rotate freely, and coated with a common elastomeric material, such as white rubber, facilitating the rotation of the image-bearing panel in a continuous fashion, devoid of interruptions.

The essential question of the present invention is found in the use of a material in the main shaft, that practically eliminates the friction with the panel while simultaneously providing sufficient adherence of the latter on the said main shaft in order to provide a smooth, even and continuous movement of the panel.

According to a particularly preferred embodiment of the invention, the panel is comprised by a sheet, a web or a film.

In an even more advantageous mode, this sheet, web or film is <BR> <BR> a transparent photograph, i. e. , a photographic substrate on transparent polymer containing the images to be displayed.

The continuous movement of the image functions by adhering with pressure the leading end of the transparent photograph to the trailing end thereof in the horizontal direction between the three shafts.

This continuous movement of the image occurs vertically in the downward direction, in a substantially convex shape, over the cold- molded polymer support that serves as a guide for the oval movement of the image and is secured to the internal cowling of the display device.

In a preferred version of the invention, the convex curve of movement and of the support profile over which the transparent photograph slides is elliptic.

According to another version of the invention, the polymer whereof the support is made is polyethylene terephthalate glycol, known by the acronym PETG. This polymer contains the gel that facilitates the sliding of the transparent photograph.

The reverse side of the transparent photograph may receive a protective laminated layer which will smooth the friction thereof against the support during the continuous movement, without causing wear to the emulsion of the transparent photograph and without impairing the quality of the image of the visual communication medium.

This laminated protective layer on the back side of the transparent photograph consists in a self-adhesive film that is applied with or without heating.

The present invention may be better understood by reference to a detailed description thereof given by way of illustration with reference to the drawings, wherein: Figure 1 is a schematic perspective view of a message display board panel incorporating the mechanism according to the present invention.

Figure 2 is a top view of the display device of Figure 1.

Figure 3 is an enlarged perspective view of one side of the panel of Figure 1.

As may be seen in the drawings, the mechanism of the present invention is structured by a cowling or frame 1 that essentially has the shape of a rectangular plate over which there is deposited a support with the elliptic surface 16 made of a plastic material such as PETG (polyethylene terephthalate glycol). A sheet, web or film 15 in the case of a transparent photograph deposited on a laminated back surface has its respective ends joined to one another, e. g. by gluing the same together, and is made to rotate over this support passing by two freely rotating shafts, one upper shaft 18 and one lower shaft 19, for example coated with an appropriate rubber to allow the sliding of the transparent photograph 15 without excessive friction. The shafts 18 and 19 are attached by respective bushings 7. The transparent photograph is driven by an upper main roller 6, which is a roller driven by means of a system comprised by a movement reduction pulley 3 coaxial with this shaft 6 that receives, by means of a belt 4, the transmission of movement from a smaller pulley 2 coupled to a reduction motor assembly 1 formed by a direct current motor.

At the base of the device, corresponding to the lower part of the movement of the transparent photograph 15, this latter is secured on the lower shaft 19 by a fastening spring pin 17 that passes through an oblong slit 20 made out in the cowling 1.

Over the shaft 6 there are uniformly distributed a number of sleeves 5 that in the most preferred embodiment of the present invention are made of silicone to allow a perfect compromise between adherence and movement of the transparent photograph on the shaft 6.

Furthermore, the system includes a whole electric arrangement formed by an on-off switch 8 that only turns off the motor, a power supply 13 for the motor, a fuse holder 9 holding a fuse for protection of the electric

system, a voltage selection switch 10, to allow the use of the device in different utility networks, electronic reactors 11 and 14 to light up one or more tubular fluorescent lamps 12. In a preferred embodiment of the display device according to the present invention, the number of lamps is three since two lamps would provide a lighting that would be poorer than that which is to be expected and needed to light the display device, and four lamps would provide an excessive lighting, impairing the contact of the consumer or reader with the advertising or information message.

Other items and accessories may be aggregated to the display device as might be needed, such as support columns, on the floor or on the ceiling, product shelves, and the system may receive different types of finishing in order to improve its visual aspect.