Laser Array
AssigneeHewlett-Packard Indigo B.V.
InventorsBoaz Tagansky, Michael Plotkin, Craig Breen
Life of this patent
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Abstract
Electrophotographic print system, comprising a photosensitive medium, and a laser array being provided with a plurality of laser diodes arranged to emit light onto the photosensitive medium for varying an electrical potential on a surface of the photosensitive medium, and a plurality of heat dissipation diodes, each heat dissipation diode being arranged in proximity to a corresponding laser diode, wherein each laser diode and the corresponding heat dissipation diode are coupled to a common drive circuit and are arranged in opposite current flow directions with respect to each other, so that in use the current flows either through the laser diode or through the heat dissipation diode depending on the current flow direction in the drive circuit.
Claims13
Laser array, comprising a plurality of laser assemblies,
- the laser assembly comprising a laser diode, a corresponding heat dissipation diode, and a drive circuit arranged to conduct current to the respective laser diode and heat dissipation diode, wherein
- the laser diode and the heat dissipation diode have an opposite polarity with respect to each other within the laser assembly, so that current either flows through the laser diode or through the heat dissipation diode, depending on the current flow direction in the drive circuit, and
- the heat dissipation diode is arranged in close proximity to the corresponding laser diode so that in use the laser assembly dissipates an approximately equal amount of heat irrespective of the laser diode or the heat dissipation diode being switched on.
Electrophotographic print system, comprising
- a photosensitive medium, and
- a laser array being provided with
- a plurality of laser diodes arranged to emit light onto the photosensitive medium for varying an electrical potential on a surface of the photosensitive medium, and
- a plurality of heat dissipation diodes, each heat dissipation diode being arranged in proximity to a corresponding laser diode,
- wherein each laser diode and the corresponding heat dissipation diode are coupled to a common drive circuit and are arranged in opposite current flow directions with respect to each other, so that in use the current flows either through the laser diode or through the heat dissipation diode depending on the current flow direction in the drive circuit.
Method of controlling light emission intensity onto a photosensitive medium, comprising
- turning on a laser diode,
- current flowing through a drive circuit and through the laser diode in a first direction,
- the laser diode emitting light onto the photosensitive medium,
- turning off the laser diode by switching a polarity in the drive circuit,
- current flowing through the drive circuit in a second direction that is opposite to the first direction, and through a heat dissipation diode corresponding to the laser diode that is arranged in an opposite polarity with respect to the laser diode, and
- the assembly of the laser diode and the heat dissipation diode dissipating a relatively constant amount of heat before and after switching the polarity.
Dependencies are inferred from the claim text.