US 6,554,395 B2 · Print head servo and velocity controller with non-linear compensation

Abstract

A print head motor control system uses a desired function of print head position versus time and a measured print head position to form an error signal. The print head controller forms a motor drive signal from the sum of a first term corresponding to the square root of the absolute value of the error signal and a second term corresponding to a dead band signal having a predetermined slope if said error signal exceeds a predetermined value. The desired function of print head position versus time may be formed by double integrating a desired function of print head acceleration versus time. The print head motor control preferably also includes a velocity loop subtracting a print head velocity estimated from the measured print head position from the sum. The print head motor control is preferably implemented using a microprocessor.

Claims15

Dependent claims

A method of print head motor control comprising the steps of:

forming a desired function of print head position versus time;
measuring the print head position;
forming an error signal from a difference of a current desired print head position and a measured print head position;
and
forming a motor drive signal from the sum of a first term corresponding to the square root of the absolute value of the error signal and a second term corresponding to a dead band signal having a predetermined slope if said error signal exceeds a predetermined value.

2 more elements

A printer comprising:

a print head movably mounted to a carriage for scanning across a page to be printed;
a drive motor coupled to said print head bidirectionally driving said print head across said page to be printed;
a position sensor mounted on said print head generating a position signal indicative of a position of said print head within said page to be printed;
a print head controller connected to said drive motor and receiving said position signal from said position signal, said print head controller operable to
form a desired function of print head position versus time,
form an error signal from a difference of a current desired print head position and said position signal, and
supply a motor drive signal to said drive motor from the sum of a first term corresponding to the square root of the absolute value of said error signal and a second term corresponding to a dead band signal having a predetermined slope if said error signal exceeds a predetermined value.

4 more elements

Dependencies are inferred from the claim text.

Print head servo and velocity controller with non-linear compensation

Life of this patent

Print head servo and velocity controller with non-linear compensation

Life of this patent

Abstract

Claims15