Stepper motor driven print head

Patent metadata

Field	Value
Publication number	US-10875335-B2
Application number	US-201414901576-A
Country	US
Kind code	B2
Filing date	Oct 10, 2014
Priority date	Jun 27, 2013
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

A thermal transfer printer comprising: first and second spool supports each being configured to support a spool of ribbon; a ribbon drive configured to cause movement of ribbon from the first spool support to the second spool support; a printhead configured to selectively transfer ink from the ribbon to a substrate, the printhead pressing the print ribbon and substrate together against a print roller; a substrate drive configured to cause movement of a substrate past the printhead; a sensor configured to monitor rotation of the print roller and generate a signal indicative thereof; and a controller configured to determine a measure of movement of the substrate and/or ribbon past the print roller based on the signal output by the sensor.

First claim

The invention claimed is:

1. A thermal transfer printer comprising:
first and second spool supports each being configured to support a spool of ribbon;
a ribbon drive configured to cause movement of ribbon from the first spool support to the second spool support;
a printhead configured to selectively transfer ink from the ribbon to a substrate, the printhead pressing the print ribbon and substrate together against a print roller;
a substrate drive configured to cause movement of the substrate past the printhead;
a sensor configured to monitor rotation of the print roller and generate a signal indicative thereof; and
a controller configured to determine a measure of movement of the substrate and/or ribbon past the print roller based upon the signal output by the sensor and a quantity indicative of a diameter of the print roller;
wherein the quantity indicative of the diameter of the print roller is a quantity indicative of an effective diameter of the print roller as determined by the controller based upon a quantity indicative of the pressure applied by the printhead to the ribbon and the substrate against the print roller.

2. A thermal transfer printer according to claim 1 , wherein said quantity indicative of the pressure is at least partially based upon the force applied by the printhead to the ribbon and substrate against the print roller.

3. A thermal transfer printer according to claim 1 or 2 , wherein said quantity indicative of the pressure is at least partially based upon a parameter indicating a size of the print roller.

4. A thermal transfer printer according to claim 1 , further comprising a motor configured to cause movement of the printhead towards and away from the print roller; wherein the controller is configured to provide a control signal to the motor to cause the motor to press the printhead against the print roller.

5. A thermal transfer printer according to claim 4 , wherein the controller is configured to determine the control signal by:
obtaining a pressure to be applied to the print roller; and
generating a control signal to be applied to the motor to cause the printhead to press against the printing surface with the obtained pressure.

6. A thermal transfer printer according to claim 4 or 5 , wherein the motor shaft is coupled to the printhead by an inelastic coupling.

7. A thermal transfer printer according to claim 6 , wherein such the elasticity provided by internal components of the motor is greater than the elasticity of the coupling between the printhead and the motor shaft.

8. A thermal transfer printer according to claim 7 , wherein the elasticity provided by the internal components of the motor is provided by deviation of a rotor of the motor relative to the magnetic field in the stator of the motor from a position to which the rotor is commanded to move.

9. A thermal transfer printer according to claim 6 , wherein the quantity indicative of an effective diameter of the print roller is determined based upon said control signal.

10. A thermal transfer printer according to claim 1 , wherein the substrate drive comprises a substrate motor arranged to cause movement of the substrate past the printhead.

11. A thermal transfer printer according to claim 10 , wherein the substrate drive comprises a stepper motor and the controller controls the stepper motor.

12. A thermal transfer printer according to claim 1 , wherein the controller controls the substrate drive at least partially based upon the signal output by the sensor.

13. A labelling machine comprising a thermal transfer printer according to claim 1 , wherein the substrate is a label web comprising a plurality of labels affixed to a backing web, and the substrate drive comprises a first and second substrate spool supports, the first substrate spool support being arranged to support a spool of label carrying web and the second substrate spool support being arranged to support a spool of web from which at least some labels have been removed.

14. A labelling machine according to claim 13 , further comprising a labelling station arranged to remove labels from the label carrying web, the labelling station being located on a label path between the first and second substrate spool support.

15. A labelling machine comprising:
first and second ribbon spool supports each being configured to support a spool of ribbon;
a ribbon drive configured to cause movement of ribbon from the first spool support to the second spool support;
first and second label spool supports, the first label spool support being configured to support a spool of label carrying web and the second label spool support being configured to support a spool of web from which at least some labels have been removed;
a printhead configured to selectively transfer ink from the ribbon to labels of the label web, the printhead pressing the print ribbon and label web together against a print roller;
a label web drive configured to cause movement of the label web past the printhead;
a sensor configured to monitor rotation of the print roller and generate a signal indicative thereof; and
a controller configured to determine a measure of movement of the label web and/or ribbon past the print roller based upon the signal output by the sensor and a quantity indicative of a diameter of the print roller;
wherein the quantity indicative of the diameter of the print roller is a quantity indicative of an effective diameter of the print roller as determined by the controller based upon a quantity indicative of the pressure applied by the printhead to the ribbon and the substrate against the print roller.

Assignees

• Videojet Technologies Inc

Inventors

• Mcnestry Martin
• Hart Philip
• Pfeffer Gary

Classifications

• B41J25/312 Primary

  with print pressure adjustment mechanisms, e.g. pressure-on-the paper mechanisms · CPC title

• B41J33/16

  with drive applied to spool or spool spindle · CPC title

• B41J3/4075

  Tape printers; Label printers · CPC title

• B41J33/003 Primary

  Ribbon spools · CPC title