In the commercial world of today more and more advertising is made. Stores are using advertisement posters to communicate their messages to the public. However, space is sometimes a limiting factor when it comes to exposing posters. To solve this problem it is known to use devices, which are capable of changing posters, by for instance rotating an “endless” belt or band consisting of many individual posters through a cylinder arrangement. In this fashion one surface may be used to display several different messages or advertisements.
However many of the known devices are usually complicated to handle, because of their complex design. For instance it might take a long time and be complicated to change a set of posters for new ones. The complexity with many different parts also contributes to the high cost for such devices.
One improved device is described in EP 883 875. This device comprises a drum on which different posters can be wound up and unwound. The posters are attached to the drum with the same distance therein between and by rotating the drum in a certain way and in different directions it is possible to show one poster at a time. A mechanical circuit controls the timing of the drums rotation, even if it is mentioned that it would be possible to use an electrical circuit. However, it is not further described how the electrical circuit could be realised. The mechanical circuit is complex and consists of a lot of different parts. One other aspect of the mechanical circuit is that it is noisy and different timing aspects have to be set in a mechanical way, which make it limited when it comes to set different time intervals.
A drawback with the device according to EP 883 875 is that it requires a strong motor when the posters or any other flexible objects become large and thereby heavy. Thus, it is important with a sufficient power supply. A large motor is of course also noisier than a small one.