Abstract
A two dimensional large scale laser digitizer system with a cordless cursor was developed. The coordinate detecting scheme of this digitizer is fundamentally based on the triangulation method, in which two laser-rays are scanned by the rotating plane mirrors, reflected backward by the cursor, reflected again by the rotating mirrors, and detected by optical sensors. From angles in which the cursor reflections are detected, we can determine the position of the cursor. But this method involves several problems about optical alignment and its calibration especially when it is applied to a large scale digitizer. In this paper an appropriate model for calculating the coordinate of the cursor is proposed. The model provides an easy way for setting devices and achieving high accuracy of a measurement.
The time required for setting the device is about 5 minutes and the average accuracy of 2m×6m and 3m×4m digitizer is within±0.15mm.
