Browse Prior Art Database

DUOBINARY MODULATION APPLIED TO PULSE IMAGING

IP.com Disclosure Number: IPCOM000024450D
Original Publication Date: 1980-Aug-31
Included in the Prior Art Database: 2004-Apr-02
Document File: 1 page(s) / 59K

Publishing Venue

Xerox Disclosure Journal

Abstract

Reversing the phase of the carrier to an Acousto-Optic (A/O) modulator of a laser driven raster output scanner (ROS) system between pulses to increase the bandwidth of the modulator is known. This successfully increases the bandwidth of the ROS system when modulating with an alternating 1/0 bit pattern. In this case, the effective bandwidth of the system is doubled. However, for other bit patterns, the result is not as satisfactory.

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XEROX DISCLOSURE JOURNAL

DUOBINARY MODULATION APPLIED TO

PULSE IMAGING U.S. Cl. 358/300

Sidney Marshall

Proposed Classification

Int. C1. H04n 1/30

Reversing the phase of the carrier to an Acousto-Optic (A/O) modulator of a laser driven raster output scanner (ROS) system between pulses to increase the bandwidth of the modulator is known. This successfully increases the bandwidth of the ROS system when modulating with an alternating 1/0 bit pattern. In this case, the effective bandwidth of the system is doubled. However, for other bit patterns, the result is not as satisfactory.

In The Duobinary Technique For High Speed Data Transmission, (IEEE Transactions on Communications and Electronics, May 1963), Adam Lender proposed a new data transmission technique that effectively doubles the transmission rate for data communications. He proposed representing zero by 0 volts and one by + or - 1 volts. Since the interest there was in data communications, good separation between the zero and one states was required. However, the close similarity to A/O modulator applications where either polarity carrier represents light and no carrier represents no light may be noted.

' It is proposed that a modulation algorithm be provided to reverse the carrier phase where there are an odd number of time intervals between carrier pulses. Where there are an even number of time intervals, the carrier phase is not changed. This minimizes the required bandwidth for all data patterns and not j...