04507796 is referenced by 26 patents and cites 7 patents.

A printer having greatly reduced radio frequency interference from the system clock signal therein is provided by angle modulating the system clock signal in accordance with a desired modulation signal. The modulation signal is chosen so as to spread and thereby reduce the energy level of the system clock signal at the carrier and at the harmonics without interfering with proper detection of the system clock signal by the electronic circuits within the printer requiring the clock signal for proper timing. In a first embodiment the angle modulation is provided by an FM modulator responsive to a modulating signal which is either sinusoidal or randomly varying in nature. In a second embodiment the angle modulation is provided by an arrangement which combines a modulated subcarrier with the basic clock frequency in a phase locked loop.

Title
Electronic apparatus having low radio frequency interference from system clock signal
Application Number
6/435400
Publication Number
4507796
Application Date
October 20, 1982
Publication Date
March 26, 1985
Inventor
David M Stumfall
Santa Ana
CA, US
Agent
Fraser and Bogucki
Assignee
Printronix
CA, US
IPC
H03B 29/00
H04L 7/00
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