Browse Prior Art Database

Light Pen Verification

IP.com Disclosure Number: IPCOM000094388D
Original Publication Date: 1966-Oct-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Criscimanga, TN: AUTHOR

Abstract

This is a compact digit display device, adaptable in panels and consoles, for displaying numerals 0... 9 in a single or double sided visual apparatus. The illumination of a single light bulb is necessary for each number.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 87% of the total text.

Page 1 of 1

Light Pen Verification

This is a compact digit display device, adaptable in panels and consoles, for displaying numerals 0... 9 in a single or double sided visual apparatus. The illumination of a single light bulb is necessary for each number.

The digit display comprises seven plexiglass segments 11... 17.

In a graphic display system using a cathode ray tube and light pen for detecting selected elements in the display, the enlarged field of view of the light pen photocell or parallax distortion to the operator can produce detection of a nonselected element. Since light pen detection can initiate a data processing, programming or operator-controlled sequence,it is desirable that verification, indicating the specified target is detected, be provided before the light pen is activated.

This system provides a visual verification of light pen detection by causing the display element at which the pen is aimed to blink or be otherwise light modulated if properly in the light pen's field of view. An extra bit in the character format designated a blink bit is employed and stored with the horizontal and vertical positioning signals of the coded character in the display buffer which provides the signals for CRT regeneration. On the next regeneration cycle, the first bit position of the position registers is sampled, the blinking bit is detected and used to actuate a free-running oscillator to modulate the intensity control signal.

The oscillator can either produce blank-unbl...