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Variable Print Hammer Control for On The Fly Printing

IP.com Disclosure Number: IPCOM000087393D
Original Publication Date: 1977-Jan-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Barrow, NF: AUTHOR [+2]

Abstract

It is known that in order to achieve high print quality in disk printers it is desirable to vary the amount of force with which the hammer is driven, dependent upon the size of the particular character being printed. Varying the force of the hammer can be achieved by varying the length of the pulse which activates the hammer.

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Variable Print Hammer Control for On The Fly Printing

It is known that in order to achieve high print quality in disk printers it is desirable to vary the amount of force with which the hammer is driven, dependent upon the size of the particular character being printed. Varying the force of the hammer can be achieved by varying the length of the pulse which activates the hammer.

It is also known that, in on-the-fly disk printers where the carrier is not moving at a constant speed, it is desirable to vary the firing time of the hammer dependent upon the speed of the carrier.

The position at which the printing takes place is primarily dependent upon the starting point of the voltage pulse which fires the hammer while pulse-width variations control the magnitude of impact. However, there is a secondary effect whereby the length of the voltage pulse also affects the position at which printing occurs.

The reason for this secondary effect is that if the hammer is driven harder it travels faster and reaches the impact point sooner.

Improved print quality can be achieved by controlling both the time at which the voltage pulse initiates hammer firing and the length of the pulse used to fire the hammer. A convenient way of controlling both of these parameters is by a microprocessor. In such a system, only software changes are required to make alterations over a wide range of pulse width and initiation times. The microprocessor can control the hammer firing pulse length and initiation time in response to a combination of parameters, such as the particular character being printed and the speed of the carrier...