Data reader and methods for imaging targets subject to specular reflection

Abstract

A data reader such as for example an imaging reader with a CCD or CMOS imager or the like, having multiple images of a target item illuminated or acquired from different directions in which the image signals are combined into a complete image of the item or selected portions of the item being read such that specular reflection (over-saturated regions of the sensor array) are minimized or eliminated. In one example data reader configuration, multiple illumination sources such as first and second rows of light emitting diodes (LED's) are aimed at the item being scanned from different directions. The illumination sources are alternately pulsed and return signals are collected at one or more sensor arrays. A selected non-saturated return signal from one of the illumination sources, or selected non-saturated portions of return signal from both of the illumination sources are processed to generate a complete non-saturated image of the target. In one preferred processing scheme, assuming that each of the LED's is capable of illuminating the entire target (e.g. a barcode), a pixel-by-pixel minimum is taken of the two images thereby producing an image with specular reflection minimized or nearly eliminated.

Description

technical field [0001] [0001] The field of the disclosure relates to imaging and collection devices, and more particularly to illumination, collection and imaging methods and devices for optically coded reading, and other data and image capture devices. Background technique [0002] [0002] Image capture and other data reading devices are used to read optical codes, obtain data and capture diverse images. A common data acquisition device is an optical code reader. A typical light code consists of a pattern of black elements and light spaces. There are various types of optical encodings, including one-dimensional encodings (such as UPC and EAN / JAN barcodes) and two-dimensional encodings (such as PDF-417 and Maxicode). For convenience, certain embodiments described herein relate to the capture of one-dimensional barcodes. However, embodiments are also useful for other optical codes, symbols, and other images, such as fingerprint capture. Nothing herein should be construed a...

AI Technical Summary

Problems solved by technology

[0004] [0004] The present inventors have recognized that light from high intensity illumination sources can reflect off certain surfaces, such as metal cans that produce too high intensity reflections and thus oversaturation of the sensor array resulting in ineffective detection

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