Abstract: A system and method for automatically calibrating a scale, particularly a scanner-scale of a POS system, in which the scale is calibrated via an on-board calibration system including an accelerometer that actually measures the acceleration due to gravity factor for a given location/time and then uses this measured factor to perform a calibration sequence. An example calibration method may include the steps of (a) performing an initial calibration on the scanner-scale during assembly; (b) providing the scanner-scale with an on-board accelerometer operable to measure gravity acceleration constants for the current location; and (c) running a calibration routine using the specific calibration data obtained from the measurement in step (b) to calibrate the scale. In one configuration, the system may also use other sensors, including temperature and humidity sensors, to provide further calibration constants for use in calibrating the accelerometer and the scale strain gage.

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.

Abstract: Various improved imager-based optical code readers and associated methods are disclosed herein. According to one embodiment, an imager-based method reads an optical code (which may be, for example, a linear optical code such as a bar code) on an object in a viewing volume. The method comprises dividing an image plane into a plurality of strip-shaped sections, viewing the object in the viewing volume from a plurality of perspectives, forming a plurality of strip-shaped images corresponding to the plurality of perspectives, respectively, thereby creating a composite image containing data from a plurality of perspectives, and processing at least a portion of the composite image so as to ascertain the information encoded in the optical code on the object in the viewing volume. Certain embodiments can mimic the performance of a laser-based scanner without a laser or moving parts but instead utilizing an electronic imaging device such as an imager.

Abstract: An imaging system comprises a rolling-reset imager that forms an electronic image of an object, a light source illuminating the object with pulsed light, and a bandpass optical filter disposed between the object and the rolling-reset imager. The pulsed light has an illumination frequency spectrum and an illumination pulse width defining an effective exposure time for forming the image of the object. The bandpass optical filter has a frequency pass band permitting transmission of a significant portion of the illumination frequency spectrum while at least approximately inhibiting transmission of at least some light having frequencies outside the illumination frequency band. An imaging method illuminates an object with light in a given frequency range, so that the illumination light reflects from the object along with background light. The method filters the reflected light so as to attenuate at least some of the background light by a greater attenuation factor than the illumination light.

Abstract: Methods and systems better detect edges in a binary optical code, such as a bar code. One method constructs a threshold signal to be used for comparison with an equalized undifferentiated scan line signal imperfectly representing a binary optical code. The method comprises detecting peaks in the equalized undifferentiated scan line signal; determining midpoints between successive detected peaks; and generating a smooth signal based on the midpoints. The generated signal is the threshold signal. In one version of the method, the generating step comprises interpolating between successive midpoints so as to result in a signal passing through the midpoints and low-pass filtering the signal passing through the midpoints so as to result in a filtered signal, which is the threshold signal. In another version of the method, the generating step comprises performing regression using the midpoints so as to generate a signal curve that fits the midpoints according to a criterion.

Abstract: Disclosed are embodiments of methods, systems, and apparatus for providing virtual scan lines in an imaging system that compensate for the optical distortion associated with the system. In some embodiments, the virtual scan lines may be curved or angled according to their position in the Field of View (FOV) of the imaging system to compensate for the distortion. Some embodiments may provide for virtual scan lines that are preconfigured to compensate for a typical or pre-selected level and type of optical distortion. Other embodiments may be configured to measure or otherwise ascertain the actual distortion of the optical lens and/or other components of the system and generate a virtual scan line pattern that compensates for the measured distortion.

Abstract: An imaging system comprises a rolling-reset imager that forms an electronic image of an object, a light source illuminating the object with pulsed light, and a bandpass optical filter disposed between the object and the rolling-reset imager. The pulsed light has an illumination frequency spectrum and an illumination pulse width defining an effective exposure time for forming the image of the object. The bandpass optical filter has a frequency pass band permitting transmission of a significant portion of the illumination frequency spectrum while at least approximately inhibiting transmission of at least some light having frequencies outside the illumination frequency band.

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.

Abstract: Methods and systems are disclosed for processing of 2-D images of optical code symbols having information bearing characteristics in predominantly a single dimension (such as a linear barcode). In a preferred system, pixel summing or averaging is used to generate virtual scan lines for imaging of encoded symbols to improve the signal to noise ratio (SNR) of the resulting virtual scan lines. For example, pixel summing or averaging of an imaging array may be performed in a direction orthogonal to the virtual scan line direction in order to increase the SNR of the virtual scan line signal over what can be achieved with virtual scan lines created using a single image pixel for each virtual scan line pixel. The increased SNR offered by this technique of pixel summing or averaging of an imaging array may allow capture of images with reduced exposure time, enabling capture of images of objects moving at high speed without the necessity of high intensity light sources.

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.

Abstract: A data reader and method for data reading, such as a barcode scanner, wherein the scan pattern generating optics and other features are optimized for different modes of operation. In a preferred embodiment, different patterns are projected from different apertures in the scanner housing, one scan pattern optimized for handheld operation and the other optimized for fixed operation. Other optimizable features include the presence or absence of an aiming beam, which may be generated from the same laser source as the scan pattern or from another source, and enabling or disabling decoding of the received signal during a portion of a facet wheel rotation. Decoding may be disabled while the scan line(s) for handheld use is generated unless a switch or trigger is actuated.

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.

Abstract: In one form, an imaging system comprises an imager that forms an image of an object in a field of view, a rotationally symmetric lens assembly disposed between the imager and the object, and an equalizer. The rotationally symmetric lens assembly provides increased collection efficiency for a given depth of field, whereby the rotationally symmetric lens assembly causes aberration, compared to a well-focused lens. The rotationally symmetric lens assembly comprises a front negative lens, a rear positive lens, and an aperture positioned between the front and rear lenses. The equalizer, which is connected to the imager, receives image data and at least partially compensates for the aberration caused by the rotationally symmetric lens assembly.

Abstract: Systems better detect transitions in a binary optical code signal and thus better detect edges in binary optical codes, such as bar codes. The optical code signal imperfectly indicates perceived regions of relatively dark and light areas arranged in an alternating pattern as part of an optical code. That signal is differentiated to form a first derivative. Due to various non-ideal conditions, the first derivative may have a series of successive local peaks of the same polarity. Peaks in the series having a peak value less than a previous peak value in the series are ignored, thereby resulting in a set of unignored peaks. From the unignored peaks in the series is chosen the one peak occurring last in order. According to the chosen peak, there is generated a signal more reliably indicating the true edge position between light and dark areas in the pattern.

Abstract: A data reader and method for data reading, such as a barcode scanner, wherein the scan pattern generating optics and other features are optimized for different modes of operation. In a preferred embodiment, different patterns are projected from different apertures in the scanner housing, one scan pattern optimized for handheld operation and the other optimized for fixed operation. Other optimizable features include the presence or absence of an aiming beam, which may be generated from the same laser source as the scan pattern or from another source, and enabling or disabling decoding of the signal received signal during a portion of a facet wheel rotation. Decoding may be disabled while the scan line(s) for handheld use is generated unless a switch or trigger is actuated.

Abstract: A data reader and method for data reading, such as a barcode scanner, wherein the scan pattern generating optics and other features are optimized for different modes of operation. In a preferred embodiment, different patterns are projected from different apertures in the scanner housing, one scan pattern optimized for handheld operation and the other optimized for fixed operation. Other optimizable features include the presence or absence of an aiming beam, which may be generated from the same laser source as the scan pattern or from another source, and enabling or disabling decoding of the signal received signal during a portion of a facet wheel rotation. Decoding may be disabled while the scan line(s) for handheld use is generated unless a switch or trigger is actuated.

Abstract: A data reader and method for data reading, such as a barcode scanner, wherein the scan pattern generating optics and other features are optimized for different modes of operation. In a preferred embodiment, different patterns are projected from different apertures in the scanner housing, one scan pattern optimized for handheld operation and the other optimized for fixed operation. Other optimizable features include the presence or absence of an aiming beam, which may be generated from the same laser source as the scan pattern or from another source, and enabling or disabling decoding of the signal received signal during a portion of a facet wheel rotation. Decoding may be disabled while the scan line(s) for handheld use is generated unless a switch or trigger is actuated.

Abstract: A data reader and method for data reading, such as a barcode scanner, wherein the scan pattern generating optics and other features are optimized for different modes of operation. In a preferred embodiment, different patterns are projected from different apertures in the scanner housing, one scan pattern optimized for handheld operation and the other optimized for fixed operation. Other optimizable features include the presence or absence of an aiming beam, which may be generated from the same laser source as the scan pattern or from another source, and enabling or disabling decoding of the signal received signal during a portion of a facet wheel rotation. Decoding may be disabled while the scan line(s) for handheld use is generated unless a switch or trigger is actuated.

Abstract: A data reader and method for data reading, such as a barcode scanner, wherein the scan pattern generating optics and other features are optimized for different modes of operation. In a preferred embodiment, different patterns are projected from different apertures in the scanner housing, one scan pattern optimized for handheld operation and the other optimized for fixed operation. Other optimizable features include the presence or absence of an aiming beam, which may be generated from the same laser source as the scan pattern or from another source, and enabling or disabling decoding of the signal received signal during a portion of a facet wheel rotation. Decoding may be disabled while the scan line(s) for handheld use is generated unless a switch or trigger is actuated.