Abstract

A light pen for use in data imput to data processing equipment, has an adjustable tip assembly wherein the tip switch sensitivity and tactile feel or feedback to the user can be varied according to user preferences and particular applications. In one mode, the pen can be set for a normal, longer throw of the switch, so as to provide and require a definite touch or push action on the part of the user in order to actuate the switch. In another mode, the tip switch characteristics can be adjusted for a very light feel, so as to permit delicate input such as handwriting or drawing. The tip assembly includes an adjustable stop member provided within the tip housing, to provide a variable limit for the travel of the tip structure. In a preferred form, the adjustment includes contact surfaces on said tip structure and said stop member, at least one of which includes and annular shape lying in a plane which is inclined at an angle to perpendicular with respect to the axis of the light pen, so that varying the rotational position of the tip structure and stop member changes the effective length of travel and sensitivity of the light pen actuation.