Abstract: Evaluating a symbol on an object can include acquiring a first image of the object, including the symbol. A second image can be derived from the first image based upon determining a saturation threshold for the second image and possibly scaling of pixel values to a reduced bit-depth for the second image.

Abstract: Evaluating a symbol on an object can include acquiring a first image of the object, including the symbol. A second image can be derived from the first image based upon determining a saturation threshold for the second image and possibly scaling of pixel values to a reduced bit-depth for the second image.

Abstract: Evaluating a symbol on an object can include acquiring a first image of the object, including the symbol. A second image can be derived from the first image based upon determining a saturation threshold for the second image and possibly scaling of pixel values to a reduced bit-depth for the second image.

Abstract: A multi-bit digitizer (30) for a barcode reader detects the presence of edges of a scanned barcode symbol, and also measures the strength of each detected edge. A polarity or edge direction signal (8) indicates the direction of each detected edge, and a timing signal (6) is representative of the timing and also, by means of a variable pulse width, the strength of each edge. A gating signal (200) indicates that the data are unreliable and invalid if the measured voltage applied to the scanner motor of the barcode reader is higher or lower than defined limit values. Any scans made at a speed which were too high or too low are rejected.

Abstract: Apparatus for reading bar code symbols including a laser light source, an optical component for scanning a reference plane, and a sensor for detecting the light of variable intensity reflected from the target. A processor determines whether the reflected light represents a spatial variation that could represent a bar code and generates an enabling signal and a controller is provided for modifying the light beam in response to the enabling signal.

Abstract: A method for combining decoded scan fragments of a bar code symbol composed of a delimited plurality of bar code elements representing an ordered sequence of data characters. The method includes scanning the symbol along a first scan path that includes a delimiter to obtain a first sequence of data characters; scanning the symbol along a second scan path that includes another delimited to obtain a second sequence of data characters; comparing the predetermined length of the lengths of the first and second sequences of data characters; and based on the comparison combining the first and second sequences to produce the ordered sequence of data characters. In a further version of the method, the first and second sequences are loaded into a stitching buffer, and a corresponding reliability or redundancy buffer is also maintained where information on the expected reliability of the individual decoded characters can be stored.

Abstract: Apparatus for reading bar code symbols including a laser light source, an optical component for scanning a reference plane, and a sensor for detecting the light of variable intensity reflected from the target. A processor determines whether the reflected light represents a spatial variation that could represent a bar code and generates an enabling signal and a controller is provided for modifying the light beam in response to the enabling signal.

Abstract: A plurality of the areas of different light reflectivity of a bar code symbol, or the like, are simultaneously illuminated, using, e.g., a beam of laser light that has an elongated cross-section. The laser light beam is swept over the symbol in a direction transverse to the elongated dimension of the illuminated region so that a two-dimensional area of the symbol is illuminated over time, until the symbol is read. The light that reflects from the illuminated region of the symbol is imaged on a linear sensor array, which is then scanned or read out to produce signals representative of spatial intensity variations of the imaged light along a linear path in the field of view.

Abstract: A method for combining decoded scan fragments of a bar code symbol composed of a delimited plurality of bar code elements representing an ordered sequence of data characters. The method includes scanning the symbol along a first scan path that includes a delimiter to obtain a first sequence of data characters; scanning the symbol along a second scan path that includes another delimiter to obtain a second sequence of data characters; comparing the predetermined length to the lengths of the first and second sequences of data characters; and based on the comparison combining the first and second sequences to produce the ordered sequence of data characters.

Abstract: A method for reading bar code symbols which enables legitimate characters recognized by the code in use to be derived from a plurality of scans corresponding to illegitimate characters not recognized by the code in use is disclosed. The method includes the steps of storing representations of the bar code symbol which cannot be decoded to produce legitimate character(s). One of the representations is improved, or corrected, using another representation, and an attempt is made at decoding the corrected representation to produce a legitimate character. If the decoding attempt is not successful, further corrections are made in order to provide a representation which may be decoded to produce a legitimate character.

Abstract: Apparatus for reading bar code symbols including a laser light source, an optical component for scanning a reference plane, and a sensor for detecting the light of variable intensity reflected from the target. A processor determines whether the reflected light represents a spatial variation that could represent a bar code and generates an enabling signal and a controller is provided for modifying the light beam in response to the enabling signal.

Abstract: Apparatus for reading bar code symbols including a laser light source, an optical component for scanning a reference plane, and a sensor for detecting the light of variable intensity reflected from the target. A processor determines whether the reflected light represents a spatial variation that could represent a bar code and generates an enabling signal and a controller is provided for modifying the light beam in response to the enabling signal.

Abstract: A bar code scanner is disclosed employing a laser source and scan mirror for generating a light beam for scanning a bar code symbol or the like. The working range for distance between the scanner and the symbol is extended by placing an optical element in the path between the laser source and the scan mirror. This optical element may be a figure of rotation such as an axicon. A slit may be positioned downstream of the axicon to block the characteristic concentric rings produced in the beam in areas perpendicular to the scan line.

Abstract: Apparatus for reading bar code symbols including a laser light source, an optical component for scanning a reference plane, and a sensor for detecting the light of variable intensity reflected from the target. A processor determines whether the reflected light represents a spatial variation that could represent a bar code and generates an enabling signal and a controller is provided for modifying the light beam in response to the enabling signal.