| 摘要 |
In addition to the conventional rolling ball 12, encoding wheels 14, 15 and buttons 23, 24, the mouse has a further pair of two-dimensional x and y coordinate input rollers 32, 33 which protrude through slots 25, 26 in the top of the housing. Each roller 32, 33 may be part of an optical encoding system and have a sprocket wheel (39, fig.4) the teeth of which are engaged by a projecting portion 41 of a torsion spring 4 mounted on a pillar 38. The user does not need to press down on the mouse to operate the additional rollers 32, 33. |
