Patent ID: 7178259

Claim:
An electronic measuring device for measuring length or distance along a surface, the device comprising: a housing; at least one wheel for engaging and rolling on the surface, the wheel being mounted on an axle, the axle being coupled to an encoder disk, the encoder disk comprising a plurality of circumferentially spaced-apart opaque sections with translucent sections disposed the opaque sections, the opaque sections and translucent sections of the encoder disk passing between an emitter and a receiver when the wheel rotates, the emitter and receiver being linked to a controller, the controller computing the length or distance traveled by the wheel by counting the number of opaque sections or translucent sections that pass between the emitter and receiver; and at least one control button on the housing, the at least on control button connected to the controller, wherein the at least one control button selects a start measurement point and an end measurement point, the start measurement point and the end measurement point being selectable relative to a position on the housing.