POSITION INDICATOR AND INFORMATION STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a position indicator and an information storage medium by which exact indicated position information without depending on a scanning system is obtained. SOLUTION: A scanning system discriminating part 30 discriminates whether the scanning system is a standard scanning type or a double density scanning type by detecting frequency components of a photodetection signal from a photosensor 18. A position calculating part 60 calculates an indicated position of a gun-type controller by measuring photodetection timing based on signals LS, LE (photodetection signals), IHS, IVS (counting timing setting signals) and CLKC (a clock signal for counting). A counting timing correcting part 52 generates the signals IHS, IVS by shifting timing which synchronizing signals HS, VS included in a video signals become active based timing correction information. A frequency switching 40 switches frequencies of CLKC so that detected resolution of the indicated position becomes identical without depending on the scanning system. Frame delay of the photodetection signal is detected based on the output timing of the video signal of an all black picture and output timing of the indicated position information corresponding to the output timing of the video signal.