| 摘要 |
<p>PURPOSE:To prevent influences caused by the erroneous detection or fluctuation, etc., of a sensor and to obtain stable coordinate information by calculating coordinate values to one instructed point by the several kinds of methods, deciding the existence of the sensor executing the erroneous detection when those calculated values are different for more than a specified value, specifying the erroneous detecting sensor and suitably selecting the coordinate calculating method to be hardly affected by the sensor. CONSTITUTION:First of all, two methods for calculating the (x) coordinates of the instructed point are assumed as follows; (5): an x12 coordinate is calculated by sensors S1 and S2, an x13 coordinate is calculated by sensors S1 and S3 and the (x12, x13) is transformed to the (x) coordinate by first-order transform, (6): an x02 coordinate is calculated by sensors S0 and S2, an x03 coordinate is calculated by the sensors S0 and S3 and the coordinate (x02,x03) is transformed to the (x) coordinate by the first-order transform. At such a time, when one of the four sensors erroneously calculate the integer-multiple value of a wavelength only by + or -1, a certain formula is established concerning the (x) coordinate values x(5) and x(6) to be calculated by the respective methods (5) and (6) as mentioned above. In this case, lambda is the wavelength and rk is a true distance between the erroneous detecting sensor and a pen. Then, by investigating which sensor satisfies a formula 1, the erroneous detecting sensor can be specified.</p> |
