Light Pen Tip
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
Light pens in present common use, for identifying positions on the face of a CRT display at which data display or modification is desired, utilize a relatively wide tip with an aperture. The width of the input surface of the light pen tip is such that it obscures geometrical lines or small indicia close to the point at which the light pen is placed. See Fig. 1. The end face 1 and the aperture 2 in existing plastic tip housing 3 are shown. Screw threads at shoulder 4 attach the tip to the sensing element in the light pen (not shown). Fig. 2 illustrates the improved tip in which the end surface 5 is slightly rounded and the existing aperture 2 is elongated so that portion 3A is greater than that in Fig. 1. The shoulder 4 has the same diameter and existing threads as the older tip in Fig. 1.