US 6,606,330 B2Granted

Laser drive compensation by duty cycle and power

AssigneeLexmark International, Inc.

InventorsCraig Palmer Bush, Mark Edwin Kirtley Lund, Eric Wayne Westerfield

Life of this patent

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Abstract

Laser printers are designed assuming the actual laser operates at nominal values which are the average or central values of a large batch of such lasers. The nominal values are determined and stored in permanent memory. Similarly, the values of the laser actually in the printer are determined during manufacture and also stored in permanent memory. Data to the laser is adjusted to correlate the output called for by the data with the differences in response of the laser of the printer by determining the optical output called for by the data using the nominal values stored and then finding the power needed to achieve the same output using the actual values stored. This is particularly useful with extreme duty cycles.

Claims4

Dependent claims

The method of driving an actual optical source from drive power data suitable for an optical source having nominal optical energy outputs at a range of power inputs at at least two duty cycles comprising the steps of:

storing first information defining said nominal optical energy outputs for a first duty cycle and for at least a second duty cycle,
determining from said first information the optical energy output for individual power input levels of said drive data,
storing second information defining the optical energy outputs at a range of power inputs of said actual optical source for a first duty cycle and for at least a second duty cycle,
determining from said second information the power input to said actual optical source to at least approximate said optical energy output determined from said first information, and
driving said actual optical source at said determined power input in a selected duty cycle.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/850,491Filed 7 May 2001
Published: US 2002/0163944 A17 Nov 2002
Granted: 12 Aug 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H04N 1/4005
Circuits exciting or modulating particular heads for reproducing continuous tone value scales: with regulating circuits, e.g. dependent upon…
B41J 2/442
Using single radiation source per colour, e.g. lighting beams or shutter arrangements: using lasers
H01S 5/0683
Stabilisation of laser output parameters: by monitoring the optical output parameters
H04N 1/40037
Circuits exciting or modulating particular heads for reproducing continuous tone value scales: the reproducing element being a laser