Multi-focal length imaging based portable dataform reader
AssigneeTelxon Corporation
InventorPaul Douglas Stoner
Life of this patent
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Abstract
A dataform reader which includes a hand-portable sized housing and an image assembly included within the housing. The image assembly includes a lens array or other optical system for obtaining a plurality of images of the dataform when positioned a given distance from the dataform. Each of the plurality of images is obtained relative to a different respective best focus length from the image assembly. The dataform reader further includes processing circuitry within the housing for selecting, from among the plurality of images, an image satisfying a predefined focus criteria. The image is selected based upon an evaluation of a sample from each of the images. The selected image may then be decoded.
Claims26
A dataform reader for reading a dataform, comprising:
- a hand-portable sized housing;
- an image assembly included within the housing, the image assembly including a plurality of lens assemblies, each of the lens assemblies being designed to image the dataform relative to a different respective best focus length from the image assembly in order to obtain a corresponding one of a plurality of sets of image data;
- and
- means within the housing for selecting, from among the plurality of sets of image data, by evaluating each of the plurality of sets of image data and selecting one of the sets of image data satisfying a predefined focus criteria, wherein each of the plurality of sets of image data is evaluated by sampling each of the plurality of sets of image data and selecting one of the sets of image data based on the sampled data which satisfies the predefined focus criteria.
A method for reading a dataform using a portable dataform reader, comprising the steps of:
- obtaining a plurality of sets of image data of the dataform using a plurality of lens assemblies included in the dataform reader, each of the lens assemblies being designed to image the dataform relative to a different respective best focus length from the image assembly in order to obtain a corresponding one of the plurality of sets of image data;
- evaluating each of the plurality of sets of image data, wherein the step of evaluating includes sampling each of the plurality of sets of image data;
- and
- selecting, from among the plurality of sets of image data, image data satisfying a predefined focus criteria by selecting one of the sets of image data based on the sampled data which satisfies the predefined focus criteria.
A method for reading a dataform using a portable dataform reader, comprising the steps of:
- obtaining a plurality of sets of image data of the dataform using a plurality of lens assemblies when the portable dataform reader is positioned a given distance from the dataform, each of the plurality of sets of image data corresponding to at least one of the plurality of lens assemblies and being obtained relative to a different respective best focus length from the image assembly;
- and
- selecting, from among the plurality of sets of image data, image data satisfying a predefined focus criteria wherein the step of selecting the image dataform among the plurality of sets of image data comprises sequentially accessing image data along a predefined pattern in each of the plurality of sets of image data, and generating a histogram concurrent with the sequential access, and wherein selecting includes selecting the one set of image data with the histogram that satisfies the predefined focus criteria.
Dependencies are inferred from the claim text.