LIGHT PEN, DRAWING DEVICE, AND IMAGE DISPLAY SYSTEM

摘要

PROBLEM TO BE SOLVED: To allow a user to instantly determine whether or not there is abnormality in an image display system at occurrence of trouble, and quickly take appropriate measures.SOLUTION: A light pen 50 includes: a light-receiving element 52 that receives light emitted from an image display device 30 that forms one field period in a plurality of sub fields including a timing detection sub field for generating light emission for synchronization, and outputs a light reception signal; and a light reception state display unit 57 that indicates whether or not the light-receiving element 52 is in a light reception state of receiving light emission of the timing detection sub field with the amount of light equal to or larger than a predetermined threshold.