Laser label-printer

Patent metadata

Field	Value
Publication number	US-9290009-B2
Application number	US-201514614205-A
Country	US
Kind code	B2
Filing date	Feb 4, 2015
Priority date	May 17, 2013
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A laser label printer for use with a laser markable medium includes a laser-diode fiber-coupled to an optical train, which includes a focusing lens for focusing the radiation on the medium. The focusing lens is traversed across the medium, with incremental motion of the medium between traverses, for line by line printing of the label. The printer includes a feature for protecting the focusing lens from contamination, and self-diagnostic and adjustment features.

First claim

What is claimed is:

1. Apparatus for printing a laser markable medium, comprising:
a sheet of the medium in a printing plane, the sheet having a width;
a collimating module including a collimating lens;
a focusing module including a turning mirror and a focusing lens, the focusing module being reciprocally translatable along an axis about parallel to the printing plane;
a source of laser-radiation and an optical fiber for transporting the laser-radiation from the source thereof to the collimating module and delivering the laser-radiation from a distal end thereof in a diverging beam to the collimating lens;
the collimating lens arranged to collimate the diverging beam from the optical fiber and direct the collimated beam to the focusing module, the turning mirror directing the collimated beam to the focusing lens and the focusing lens focusing the collimated beam onto the sheet at a focal distance from the focusing lens for printing on the sheet; and
a detector housed in a diagnostic module adjacent the sheet in a translation path of the focused beam, the diagnostic module covered by a diagnostic plate including a first and second slots extending therethrough, each of the slots for allowing at least part of the focused beam to enter the diagnostic module for optical access to the detector, wherein the first and second slots have a width and length greater than the beam diameter, with first and second slots being misaligned on opposite sides of the beam travel path and encroach on the beam travel path by less than the beam diameter, and wherein the ratio of the signals generated by the detector as the beam passes the first and second slots corresponds to the amount and direction of misalignment of the beam from the beam travel path and wherein the signals are delivered to an electronic module and wherein the position of the collimating module is adjusted by the electronic module responsive to the alignment signals.

2. The apparatus of claim 1 , wherein the diagnostic plate includes a third slot configured to allow the entire focused beam to enter the diagnostic module for providing a signal from the detector representative of the power of the beam.

3. The apparatus of claim 2 , wherein the diagnostic plate includes a fourth slot that provides a signal to the electronic module representative of the accuracy of focus of the focused beam.

4. The apparatus of claim 3 , wherein the position of the collimating module is adjustable by the electronic module responsive to the focus accuracy signals for keeping the focus accuracy of the focused beam about constant.

5. The apparatus of claim 1 , wherein the focal distance becomes greater as the focusing module is translated away from the collimating module and the axis is tilted with respect to the printing plane such that the beam remains focused on the sheet during the translation of the focusing module.

6. The apparatus of claim 1 , wherein the source of laser-radiation is a laser-diode.

7. Apparatus for printing a laser markable medium, comprising:
a sheet of the medium in a printing plane, the sheet having a width;
a collimating module including a collimating lens;
a focusing module including a turning mirror and a focusing lens, the focusing module being reciprocally translatable along an axis about parallel to the printing plane;
an elongated window between the focusing module and the printing plane, the window extending beyond the width of the sheet of the medium;
a source of laser-radiation and an optical fiber for transporting the laser-radiation from the source thereof to the collimating module and delivering the laser-radiation from a distal end thereof in a diverging beam to the collimating lens;
the collimating lens arranged to collimate the diverging beam from the optical fiber and direct the collimated beam to the focusing module, the turning mirror directing the collimated beam to the focusing lens and the focusing lens focusing the collimated beam through the window onto the sheet at a focal distance from the focusing lens for printing on the sheet, the window protecting the focusing lens from contamination by by-products of the printing by the focused beam; and
a diagnostic module adjacent the sheet and aligned with the portion of the window extending beyond the sheet on the side of the window opposite the focusing lens and in a translation path of the focused beam, the diagnostic module housing a detector and covered by a diagnostic plate including at least one slot extending therethrough, the slot aligned along the translation path, of the slot for allowing at least part of the focused beam to enter the diagnostic module for optical access to the detector as the focused beam translates, thereby providing a corresponding signals representative of the power of the focused beam on the sheet, the power-representative signal being delivered to an electronic module cooperative with the laser-radiation source for maintaining power of the focused beam on the sheet about constant as the window becomes contaminated by the by-products of the printing by the focused beam.

8. The apparatus of claim 7 , wherein the diagnostic plate further includes an additional slot arranged so that the detector generates a signal representative of the accuracy of focus of the focused beam.

9. The apparatus of claim 8 , wherein the position of the collimating module is adjustable responsive to the focus-accuracy representative signal for keeping the focus accuracy of the focused beam about constant.

10. The apparatus of claim 8 , the diagnostic plate further includes a pair of additional slots arranged so that the detector generates signals representative of the alignment of the translation path of the focused beam relative to the sheet-width.

11. The apparatus of claim 10 , wherein the position of the collimating module is adjustable by the electronic module responsive to the alignment representative signals for keeping the alignment of the translation path of the focused beam relative to the sheet-width about constant.

12. The apparatus of claim 7 , wherein the focal distance becomes greater as the focusing module is translated away from the collimating module and the axis is tilted with respect to the printing plane such that the beam remains focused on the sheet during the translation of the focusing module.

13. The apparatus of claim 7 , wherein the source of laser-radiation is a laser-diode.

Assignees

• Coherent Inc

Inventors

• Govorkov Sergei
• Jerman John H

Classifications

• B41J2/47 Primary

  using the combination of scanning and modulation of light · CPC title

• B41J3/4075

  Tape printers; Label printers · CPC title

• B41J2/442 Primary

  using lasers · CPC title