Patent ID: 6229528
Filing Date: 2001-05-08
Classification: G06F

Abstract:
A coordinate data output equipment, comprising:display means for displaying an image data on a screen;line pulse generating means for applying line pulse signals with a prescribed interval to each of an array of pixels constituting said display means;coordinate signal output means stacked on said display means for outputting a coordinate signal of a designated point;digital signal converting means for converting said coordinate signal to a digital signal;coordinate data calculating means for calculating a coordinate data from said digital signal;control means for letting said digital signal converting means convert said coordinate signal to said digital signal after a prescribed time period from a timing of activation of one said line pulse signal;wherein said control means counts a number of said line pulse signals from the timing of activation of one said time line pulse signal, and letting said digital signal converting means convert said coordinate signal to said digital signal after said prescribed time period from a time point when a count value of said line pulse signals attains a prescribed value;said prescribed value being determined dependent on a relation with a time necessary for a switching element constituting said coordinate data calculating means to be electrically stabilized;wherein said line pulse generating means further applies an ac converting signal having its polarity inverted at every prescribed interval to said display means;said coordinate data output equipment further comprising ac converting signal inversion detecting means for detecting inversion of the polarity of said ac converting signal; andwherein said control means has said digital signal converting means convert said coordinate signal to said digital signal if the count value of said line pulse signals attains said prescribed value and said prescribed time period has past from a time point when the polarity of said ac converting signal is not inverted.