Length measuring apparatus

摘要

Length measuring apparatus is capable of calculating an actual distance by measuring length on a map and has a display section (4) to display the actual distance thus calculated. The length measuring apparatus includes a distance data input switch (8) for inputting distance-data of a scale-reduction scale indicated on the map and a memory (3) for storing the length of the scale-reduction scale on the map, which is measured by the rotation of a rolling member (14). The length measuring apparatus automatically calculates a scale-reduction value for the map from the distance-data and the length of the scale-reduction scale stored in the memory. Accordingly, a user of the apparatus is not required to input the scale-reduction value for the map by means of keys. The required speed or time to walk a given distance may also be displayed. A scale-reduction value may also be input using switches.