Robert R Henshaw

US Patent:

44159145, Nov 15, 1983

Filed:

Jun 30, 1981

Appl. No.:

6/278965

Inventors:

Francis P. Giordano - Scarsdale NY
Robert J. Henshaw - New City NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G01D 1506
H04N 122

US Classification:

346154

Abstract:

An electrostatic gray scale printing system is disclosed having particular utility for producing gray scale images from signals received from a suitable data source such as a computer, telecommunications line, data storage device or the like. A unique, high voltage, pulse generating circuit is provided for producing gray scale voltage pulses between 300 and 600 volts to the individual styli making up said printing device. The circuit utilizes a conventional, low voltage, power supply and a low voltage gray scale intensity signal input to produce the required high voltage printing pulses. The circuit, per se, consists of a high voltage transistor having a relatively large inductance connected in its emitter-collector circuit path. Current flows in the transistor in response to an input voltage applied to the base of the transistor. The collector current is proportional to the value of the input signal divided by the emitter resistor.