Browse Prior Art Database

Wireless Light Pen

IP.com Disclosure Number: IPCOM000122421D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 72K

Publishing Venue

IBM

Related People

Dinwiddie Jr, JM: AUTHOR

Abstract

Described is a wireless light pen to be used in conjunction with cathode ray tube (CRT) displays. The light pen is constructed with its circuitry self contained within the pen so as to eliminate connecting wires which normally run from the pen to the display unit.

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Wireless Light Pen

      Described is a wireless light pen to be used in
conjunction with cathode ray tube (CRT) displays.  The light pen is
constructed with its circuitry self contained within the pen so as to
eliminate connecting wires which normally run from the pen to the
display unit.

      The wireless pen communicates with the circuitry of the CRT
through infrared detectors built into the plastic mask which
surrounds the CRT screen.  The utilization of the wireless pen
enables the pen to be used on other machines equipped with infrared
detectors, whereas a wired pen is restricted in use to the unit to
which it is wired.

      The wireless light pen, as shown in Fig. 1, is contained in
housing 10 which contains a battery, switch and the required
electronics of the light pen.  At the nose of the pen, infrared
light-emitting diode (LED) 11 is surrounded by transparent lens
portion 12 which forms the nose. The broad spectral response from the
ultra-fast broad spectral light detector 13 is located at the tip of
the nose.  Transparent lens portion 12 allows light from infrared LED
11 to be emitted around the circumference of the light pen.  Fig. 2a
is a front view, and Fig. 2b is a side view of the CRT display.
The light from LED 11 is detected by infrared detectors 14 which are
built into plastic mask 15 which surrounds CRT screen 16.  Each
detector 14 is mounted on mask 15 to provide a face across the
surface of the CRT screen so as to detect infrared...