Abstract:
A barcode imaging reader includes a housing, a window in the housing, and an imaging sensor having an array of photosensitive elements for capturing light passing through the window. The barcode imaging reader further includes an illumination arrangement for emitting an illumination light from the housing interior to illuminate a barcode target object spaced from the housing. The illumination arrangement includes (i) an illumination source within the housing operative to generate the illumination light during imaging capture, (ii) a first mirror having a shape of a toroidal surface with predominantly concave surface, and (iii) a second mirror having a shape of a toroidal surface with predominantly convex surface.
Abstract:
A substantially uniform distributed illumination pattern of light is generated on and along a symbol to be read by image capture. A solid-state imager is mounted on a tilted printed circuit board in a tilted handle of an ergonomic reader. An imaging lens assembly captures return light over a field of view from the symbol along an imaging axis, and projects the captured return light onto the imager. An illumination light source is mounted on the board for emitting illumination light at an acute angle of inclination relative to the imaging axis. An optical component includes a first lens portion with a polynomial incident surface for intercepting, bending and aligning the emitted illumination light to generate the pattern in a scan direction along the symbol, and a second lens portion with a toroidal or cylindrical aspherical surface for collimating the aligned illumination light to generate the pattern in a transverse direction.
Abstract:
A method and apparatus for estimating an optimized exposure time for an imaging-based barcode scanner. The method includes (1) determining a SNR decodability function that enables a decodability value be determined from a signal-to-noise ratio; (2) determining a blur decodability function that enables a decodability value be determined from a blur value; (3) measuring a blur and a signal-to-noise ratio for an image captured with a first exposure time; and (4) determining an optimized exposure time based on the measured blur, the measured signal-to-noise ratio, and a combined decodability function that depends upon both the SNR decodability function and the blur decodability function.
Abstract:
An aiming light assembly supported by a mobile imaging reader projects an aiming light pattern on a symbol. A controller modulates the aiming light pattern to render the aiming light pattern more visibly discernible to an operator, especially in a brightly lit ambient environment, to enable the operator to position the aiming light pattern on the symbol prior to reading.
Abstract:
A laser power control arrangement and method in an electro-optical reader for reading indicia includes an energizable laser for emitting a laser beam having an output power along a path. An internal light detector, e.g., a monitor photodiode, is mounted inside the laser for monitoring the output power of the laser. An external light detector, e.g., an auxiliary photodiode, is mounted outside the laser for monitoring the output power of the laser independently of the internal light detector. A guide, advantageously a light pipe or a diffuser, is positioned outside the laser in the path of the laser beam for guiding the laser beam from the laser to the external light detector. A controller is operatively connected to each light detector, for controlling a monitored output power of the laser beam by deenergizing the laser when the monitored output power of the laser beam exceeds a safe power level limit.
Abstract:
A variable focus imaging lens assembly for an imaging-based bar code reader for imaging a target bar code within a field of view of the imaging system, the imaging lens assembly comprising a simplified zoom lens assembly or system that provides for both focusing and adjustment of focal length of the imaging lens assembly with movement of a single group of movable lenses using one motor. The zoom lens assembly includes a stationary lens group comprising a plurality of stationary lenses and a movable lens group comprising a plurality of movable lenses movable with respect to a sensor array of the imaging system. The movable lens group is driven by a motor along a path of travel parallel to an optic axis of the imaging lens assembly, at least one lens of the plurality of stationary lenses being intermediate a pair of lenses of the plurality of movable lenses.
Abstract:
The disclosed bar code reader includes an auto-focusing component for rapidly producing in focus images. An imaging system makes use of an aiming pattern that impinges upon the coded indicia of a target. The imaging system includes a light monitoring pixel array and a focusing lens that is fixed with respect to the pixel array for transmitting an image of the target object onto the pixel array. The imaging system also includes a movable mirror mounted for movement along a path of travel to reflect light passing through the focusing lens onto the pixel array. A drive motor moves the mirror relative the lens to adjust a focus of an image of the object formed at the pixel array. An automatic focusing component of the imaging system analyzes the aiming pattern reflected from the target object and projected onto the pixel array by the lens. The automatic focusing component issues commands to the drive motor causing the mirror to move along its path of travel to a suitable position for properly focusing the target object onto the pixel array.
Abstract:
An imaging system for, and a method of, electro-optically reading a symbol located within a range of working distances from the system, utilize a solid-state imager having an array of image sensors for capturing return light from the symbol over a field of view and for generating an electrical signal indicative of the captured return light, and a controller operative for decoding the electrical signal into data indicative of the symbol, and for determining that the symbol has been successfully decoded. The symbol has a plurality of optical characteristics, such as symbol element size and contrast, which vary with working distance. A memory stores a known set of values of the size and contrast characteristics of the symbol when the symbol lies in a restricted zone within the range of working distances. The controller is further operative, after the symbol has been successfully decoded, for processing the size and contrast characteristics of the decoded symbol, and for determining that the decoded symbol has been successfully read within the restricted zone when each size and contrast characteristic lies within the known set of values stored by the memory.
Abstract:
A method and apparatus for illuminating a target object such as a bar code having areas of differing light intensity on the target. A bar code reader has a light source that is selectively activated, a screen having a slit aperture for creating a narrow light beam, a reflecting mirror for reflecting light transmitted through the slit aperture and a lens for shaping light reflected by the mirror to form an elongated target/illumination pattern.
Abstract:
An apparatus includes a first lens, a liquid lens, imaging sensor arrays, an aperture stop, and a barcode decoding system. The first lens has a fixed optical power. The liquid lens has a variable optical power. The imaging sensor arrays are operable to receive light passing through both the first lens and the liquid lens. The liquid lens is positioned between the aperture stop and the imaging sensor arrays. The barcode decoding system receives signals from the imaging sensor arrays.