| 摘要 |
<p>PURPOSE:To reduce number of amplifiers in use while eliminating an in phase noise by providing amplifiers as adders where two coordinate line groups connected in parallel in the adverse direction mutually are connected via a common line. CONSTITUTION:An X coordinate detection coordinate line group 1 and a Y detection coordinate line group 2 are divided into two groups respectively and the coordinate line groups are connected respectively in the adverse direction. the magnetic flux generated from a coordinate indicator 24 interlinks with the selected coordinate line, its induced voltage or current is amplified by an amplifier 27 via common lines 17, 18 and fed to a processor 19 via a rectifier 28 and an A/D converter 29. The processor 19 identifiers the coordinate of the tip of the coordinate indicator 24 based on the coordinate line induced voltage and the information sent to decoders 20-23 in advance. Thus, one amplifier detects the induced voltage or current of the two coordinate lines differentially and eliminates noise such as in-phase electrostatic induction noise.</p> |
