Laser printing system

Patent metadata

Field	Value
Publication number	US-2016311230-A1
Application number	US-201415103888-A
Country	US
Kind code	A1
Filing date	Dec 16, 2014
Priority date	Dec 17, 2013
Publication date	Oct 27, 2016
Grant date	—

Abstract

The invention describes a laser printing system ( 100 ) for illuminating an object moving relative to a laser module of the laser printing system ( 100 ) in a working plane ( 180 ) and a corresponding method of laser printing. The laser module comprises at least two laser arrays ( 110 ) of semiconductor lasers ( 115 ) and at least one optical element ( 170 ). The optical element ( 170 ) is adapted to image laser light emitted by the laser arrays ( 110 ), such that laser light of semiconductor lasers ( 115 ) of one laser array ( 110 ) is imaged to one pixel in a working plane ( 180 ) of the laser printing system ( 100 ) and an area element of the pixel is illuminated by means of at least two semiconductor lasers ( 115 ). The optical element does not project or focus laser light of each single semiconductor laser ( 115 ) to the working plane ( 180 ) but images the whole laser arrays to the working plane. The overlap of the laser light emitted by the semiconductor lasers ( 115 ) may improve the homogeneity of illumination or energy input and the reliability regarding malfunctions of single semiconductor lasers ( 115 ).

First claim

1 . A laser module in a laser printing system for illuminating an object moving relative to the laser module in a working plane, the laser module comprising:
at least two laser arrays comprising semiconductor lasers; and at least one optical element, wherein each optical element is configured to image a laser light emitted by the semiconductor lasers so that the laser light of one laser array is imaged onto a pixel in the working plane, and an area element of the pixel is illuminated by at least two semiconductor lasers, wherein the optical element is configured so that an object plane of the optical element with respect to the working plane does not coincide with a plane of the semiconductor lasers such that cones of the laser light emitted by adjacent semiconductor lasers overlap in the object plane.

2 . The laser module according to claim 1 , further comprising a plurality of the laser arrays.

3 . The laser module according to claim 1 , wherein the optical element comprises one lens configured to image the laser light of the laser arrays to the working plane.

4 . The laser module according to claim 1 , wherein the optical element configured such that images of the laser arrays overlap in the working plane.

5 . The laser module according to claim 1 , wherein the laser arrays are arranged in columns perpendicular to a direction of movement of the object in the working plane, the columns are staggered with respect to each other such that a first laser array of a first column is configured to illuminate a first area of the object and a second laser array of a second column configured to illuminate a second area of the object, wherein the first area is adjacent to the second area such that continuous illumination of the object is enabled.

6 . The laser module according to claim 1 , wherein the laser arrays are rectangular with a long side of a rectangle being arranged parallel to a direction of movement of the object in the working plane.

7 . (canceled)

8 . The laser printing system according to claim 16 , wherein the laser modules are arranged in columns perpendicular to a direction of movement of the object in the working plane, the columns are staggered with respect to each other such that a first laser module of a first column configured to illuminate a first area of the object, and a second laser module of a second column is configured to illuminate a second area of the object, wherein the first area is adjacent to the second area such that continuous illumination of the object is enabled.

9 . The laser printing system according to claim 8 , wherein the columns of the laser modules are arranged such that a distance between the laser modules in one column is minimized.

10 . The laser printing system according to claim 8 , wherein the laser arrays of each laser module are arranged in an elongated arrangement with a long side of the elongated arrangement being arranged perpendicular to a direction of movement of the object in the object plane.

11 . The laser printing system according to claim 8 , wherein the laser arrays of each laser module are arranged in an elongated arrangement with a long side of the elongated arrangement being arranged slanted to a direction being perpendicular to the direction of movement of the object in the working plane.

12 . The laser module according to claim 1 , wherein the optical element is configured to demagnify the image of the laser arrays in the working plane.

13 . The laser module according to claim 1 , wherein each laser array comprises a micro-lens array, the micro-lens array being arranged to lower divergence of the laser light emitted by the semiconductor lasers.

14 . The laser module according to claim 1 , comprising at least a said first and a said second laser module arranged next to each other, each laser module comprising said at least two laser arrays, wherein at least one of the two laser arrays of the first or the second laser module is arranged as an overlap laser light source such that in operation at least one defined area element in the working plane can be illuminated by the overlap laser light source and a laser array of the laser module arranged next to the laser module comprising the overlap laser light source.

15 . A method of laser printing, the method comprising:
moving an object in a working plane relative to a laser module; emitting a laser light by the laser module comprising at least two laser arrays of semiconductor lasers and at least one optical element; and imaging the laser light emitted by the semiconductor lasers by the optical element, such that laser light of one laser array is imaged to a pixel in the working plane, and an area element of the pixel is illuminated by at least two semiconductor lasers, wherein the optical element is configured such that an object plane of the optical element with respect to the working plane does not coincide with a plane of the semiconductor lasers such that cones of laser light emitted by adjacent semiconductor lasers overlap in the object plane.

16 . A laser printing system for illuminating an object, comprising:
at least two laser modules, each laser module comprising:
at least two laser arrays comprising semiconductor lasers; and
at least one optical element, wherein each optical element is configured to image a laser light emitted by the semiconductor lasers so that the laser light of one laser array is imaged onto a pixel in the working plane, and an area element of the pixel is illuminated by at least two semiconductor lasers, wherein the optical element is configured so that an object plane of the optical element with respect to the working plane does not coincide with a plane of the semiconductor lasers such that cones of the laser light emitted by adjacent semiconductor lasers overlap in the object plane.

Assignees

• Koninklijke Philips Nv

Inventors

• Conrads Ralf Gordon
• Gronenborn Stephan
• Heusler Gero
• Möench Holger

Classifications

• B29C64/393

  for controlling or regulating additive manufacturing processes · CPC title

• G03G15/225

  using contact-printing · CPC title

• B29C64/277

  using multiple radiation means, e.g. micromirrors or multiple light-emitting diodes [LED] · CPC title

• B29C64/282

  of the same type, e.g. using different energy levels · CPC title

• B29C64/268

  using laser beams; using electron beams [EB] · CPC title