Abstract: Methods and apparatus are disclosed for selectively reading a barcode, symbol, or other indicia by either scanning the barcode with a flying-spot scanner, or by imaging the barcode, thereby improving reading performance by tailoring the reading method to the particular item that is being read. Both a flying-spot laser scanning front end and an imaging front end are incorporated in a single device. Data obtained by the selected reading method is decoded and output. A common decoder or separate decoders may be used to decode the data from the two front ends. A single image sensor may be shared between the flying-spot front end and the imaging front-end, with a limited readout area utilized for laser scanning. The size of the readout area may be adjusted based on detected target proximity. Selection of the reading mode may be based on criteria including manual input, the range of the target, or previous failed attempts to read the barcode using either reading method.

Abstract: Row signals or other typically regular signals generated by an imager during each frame period of the imager are counted to determine when to emit pulses of illumination. Methods in accordance with the preferred embodiments may facilitate synchronization of at least some of the pulses with exposures of the imager, while pulsing visible illumination at a rate in excess of the flicker fusion frequency of human vision, to thereby avoid a flicker effect. Methods in accordance with disclosed embodiments are especially useful for a data reader including an imager when visible illumination is pulsed or when it is desired to pulse one or more illumination sources (whether or not visible) at a constant rate or a minimum rate, wherein the constant or minimum rate of pulses differs from a nominal frame rate of the imager.

Abstract: An imaging system (FIG. 3) is disclosed that has a wavelength dependent focal shift caused by longitudinal chromatic aberration in a lens assembly (203) that provides extended depth of field imaging due to focal shift (213,214) and increased resolution due to reduced lens system magnification. In use, multiple wavelengths of quasi-monochromatic illumination, from different wavelength LEDs (206,207) or the like, illuminate the target, either sequentially, or in parallel in conjunction with an imager (200) with wavelength selective (colored) filters. Images are captured with different wavelengths of illumination that have different focus positions (208,209), either sequentially or by processing the color planes of a color imager separately. Extended depth of field, plus high resolution are achieved. Additionally, information about the range to the target can be determined by analyzing the degree of focus of the various colored images.