Two dimensional laser diode array using multimode lasers
AssigneeCero Products Inc.
InventorDaniel Gelbart
Life of this patent
Estimating the term…
Abstract
A two dimensional laser diode array consists of rows and columns of individual multimode laser diodes, each diode having a separate collection lens. The array is imaged at a large reduction ratio to achieve high resolution recording. In order to decrease the apparent spacing of the diodes in the scanning direction, the rows are staggered relative to the scan direction. In order to avoid variations caused by the near-field non-uniformity of multimode diodes the final spot generated on the media is an image of the aperture of the collecting lens and not of the diode facet. The larger dimension of this aperture, formed by the diffraction limited direction of the laser diode, is reduced by using anamorphic optics.
Claims13
A laser diode array for recording information on the surface of a light sensitive material comprising:
- a two dimensional array of multimode type laser diodes mounted on a substrate, each laser diode having a separate light collecting lens and each said collecting lens directing the light from each one of said diodes onto a common imaging lens, said imaging lens imaging a point not revealing a near field structure of said diodes and forming an array of spots in the form of a reduced image of said array on said material;
- one or more intermediate optical elements placed between said imaging lens and said array of laser diodes, said intermediate elements including at least one anamorphic optical element.
A laser imaging device comprising:
- a) a plurality of multimode laser diodes arranged in a two dimensional array, each of the laser diodes comprising a light source, each light source having a fast divergence axis and a slow divergence axis;
- b) a plurality of collecting lenses, one of the collecting lenses associated with each of the laser diodes, each of the collecting lenses having an aperture, each of the collecting lenses providing a far field image of the light source of the corresponding laser diode, the far field images having a larger dimension and a smaller dimension;
- c) an imaging lens, the imaging lens located to image the far field images of the light sources as an array of spots onto a recording material;
- and,
- d) an anamorphic element located in an optical path between the light sources and the recording material so as to de-magnify the larger dimension of the far field image.
Dependencies are inferred from the claim text.