Direction scaling method and apparatus for image scanning resolution control
AssigneeHewlett-Packard Company
InventorsGerald L. Meyer, David W. Boyd
Life of this patent
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Abstract
The density of pixel samples across a document is determined by employing a constant scanner sensing head sampling rate and driving the scanner head movement at a rate directly correlated to the preselected density level. The scanner operator determines the particular density and introduces a signal to motor drive controls to cause it to move across the image at the preselected rate.
Claims7
Apparatus for scaling image data sensed from a planar media which contains the image using a scanner head having an array of elements each capable of detecting the level of light reflected from the media image with the elements retained in the scanner head in a generally elongated liner configuration and an actuator for producing relative movement of a line of scanning light with respect to the media image plane so that light from a source illuminating the media image is reflected into the array elements comprising
- means generating a signal reflecting a predetermined pixel sampling density,
- enabling means having an input and including means responsive to signals present at said enabling means input for enabling the relative movement producing actuator to cause relative motion of the line of scanning light with respect to the media image plane at a rate corresponding to signals present to said enabling means input, and
- means coupling said generating means signal to said enabling means input for causing said relative movement producing actuator to establish relative movement between the media image and the line of scanning light at a rate correlated to a predetermined pixel density.
A process for scanning an image present on a planar media using a scanning head having a generally linear array of discrete light sensor elements positioned to detect light reflected from relative movement between a line of light and the media comprising the steps of
- positioning the line of light with respect to the image contained on the planar media image in proximity to the location of an initial edge of that image,
- determining the image scaling density as a function of the number of pixels per geometric unit of the image for recording,
- moving the line of light across the image from said initial image edge location at a substantially fixed rate correlated to said determining step, and
- sampling the output of the light sensor array elements at a constant rate.
Dependencies are inferred from the claim text.