| 摘要 |
The invention concerns a method of measuring lengths, in which a scanning device scans a substrate (1) with a graduated scale (2), having a graduation band, and reference marks (7) various distances apart along at least one other band (3). The signals from the scanning device are processed in a processing unit and in a display unit, the various distances between the reference marks (7) being determined in graduation-band units by scanning the graduated scale (2). From these interval-measurement signals, information is obtained in coded form on the absolute position value of the reference marks (7). At a transmission position (Pn2) on the graduation band which is displaced a whole number of graduation units (zo), where z is >/= 1, in the direction of travel from a position (Pn1) being determined, a value is fed by the processing device to the display unit as the current position of the measurement device, this value containing the absolute value of the position being determined and the shift (zo), the shift (zo) of the transmission position (Pn2) being determined from the graduation signals in the graduation band, for supplying the absolute value decoded in the processing device, with respect to the last code pulse. |
