| 摘要 |
The invention relates to an apparatus for temporarily displaying visual information, comprising a frame, a plate of material included in the frame that changes colour due to local pressure and when exposed to a magnetic field, assumes its original colour, a magnet movable along the plate, guide means for guiding the magnet along the sheet in a first position, wherein the magnet is arranged for erasing a part of the plate by its magnetic field during the movement along the plate, whereby the guide means are arranged for guiding the magnet along a path in a second position different from the first position, whereby the magnetic field generated by the magnet does not erase the first part of the plate and the device comprises operation means for operating between the first and the second position of the magnet. |
