| 摘要 |
PURPOSE:To make the dustproofing and waterproofing effects perfect by fastening belt-shaped flexible magnets at tips of belt-shaped flexible bodies in a linear encoder having a pair of belt-shaped flexible bodies for shielding a scale and a graduation reader out of a housing leaving a head. CONSTITUTION:A main scale 4 is fastened on a housing 3 fixed on the first movable body 1 and a sub scale 6 is arranged on a head 5 fixed on the second movable body 2. As both the movable bodies 1 and 2 move mutually, the scales 4 and 6 shift simultaneously and hence, the quantity of light from a light emitting element 7 changes cyclically and changes in the quantity of light of a light receiving element 8 is converted into a digital value with an electric circuit (not illustrated). In an encoder of such a type, belt-shaped flexible magnets 10a and 10b fastened at the tips of the belt-shaped flexible bodies 9a and 9b projected from concave inner surfaces 3a and 3b in the housing 3 are put tight on the side 5b of a portion 5a with a sword-shaped cross section by a magnetic force. |
