Browse Prior Art Database

Optical Signalling Systems

IP.com Disclosure Number: IPCOM000091214D
Original Publication Date: 1969-Nov-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Lynch, RJ: AUTHOR

Abstract

The signal system of drawing I is an optical RF communication arrangement. The system of drawing II is for optical radar tracking. In drawing I, output 1 of conventional radio transmitter 2 is selectively connected by switch 3 to omnidirectional antenna 4 or to light emitting diode LED 5. Impedance 6 is adjusted so that its value and the impedance of diode 5 matches the impedance of antenna 4. LED 5 is of the type which emits light in the visible or infrared region. At receiver 7, the input is selectively connected by switch 8 to omnidirectional antenna 9 or to a compatible photosensitive diode 10. Impedance 11 is adjusted so that its value and the impedance of diode 10 matches the impedance of antenna 9.

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Optical Signalling Systems

The signal system of drawing I is an optical RF communication arrangement. The system of drawing II is for optical radar tracking. In drawing I, output 1 of conventional radio transmitter 2 is selectively connected by switch 3 to omnidirectional antenna 4 or to light emitting diode LED 5. Impedance 6 is adjusted so that its value and the impedance of diode 5 matches the impedance of antenna 4. LED 5 is of the type which emits light in the visible or infrared region. At receiver 7, the input is selectively connected by switch 8 to omnidirectional antenna 9 or to a compatible photosensitive diode 10. Impedance 11 is adjusted so that its value and the impedance of diode 10 matches the impedance of antenna 9.

In one mode of operation, particularly for a secure communication system, switches 3 and 8 are connected to their respective antennae 4 and 9. The operator of transmitter 2 transmits its coded coordinate position via RF signals to the operator of receiver 7. Switches 3 and 8 are then connected to their respective diodes 5 and 10 and the operator of transmitter 1, for a predetermined time period T, transmits infrared signal pulses from diode 5. The operator of receiver 7 positions or orients diode 10 to intercept the infrared signals being transmitted by diode 5 based on the previously received coded coordinate positions. After the time period T, transmitter 2 communicates with the optical infrared signals being transmitted by diode 5 to receiver 7 via diode 8.

Preferably each diode 5 and 8 is of the type which emits light at a given spectral frequency when forward biased above a certain threshold lev...