摘要:
A bar code reader capable of working over a wider range of working angle and for a wider range of bar code densities, using improved optics and sensing elements. The optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived from the scanned bar code. The two channels have differing resolutions. Analysis of the data from the two channels provides a single decoded result. As the working angle and density vary at least one of the resolutions will be appropriate for sensing all or most of the bar coded data. The data from the channel producing a valid result can be used, or if neither channel produces a valid result by itself, data from each channel can be analyzed and valid portions of the data from both channels combined to produce the single decoded result. The different resolution of the two channels can be provided using different size photodetection areas, e.g., small and large groups of active areas on a sensor array.
摘要:
The method and apparatus of this invention facilitate operation of a bar code reader over a wider range of working angle and for a wider range of bar code densities. The invention includes improved optics and sensing elements. The optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived form the scanned bar code. The two channels have differing resolutions. Analysis of the data from the two channels provides a single decoded result. As the working angle and density vary at least one of the resolutions will be appropriate for sensing all or most of the bar coded data. The data from the channel producing a valid result can be used, or if neither channel produces a valid result by itself, data from each channel can be analyzed and valid portions of the data from both channels combined to produce the single decoded result.
摘要:
The method and apparatus of this invention facilitate operation of a bar code reader over a wider range of working angle and for a wider range of bar code densities. The invention includes improved optics and sensing elements. The optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived form the scanned bar code. The two channels have differing resolutions. Analysis of the data from the two channels provides a single decoded result. As the working angle and density vary at least one of the resolutions will be appropriate for sensing all or most of the bar coded data. The data from the channel producing a valid result can be used, or if neither channel produces a valid result by itself, data from each channel can be analyzed and valid portions of the data from both channels combined to produce the single decoded result.
摘要:
The invention facilitates operation of a bar code reader over a wider range of working angle, a wider range of distances from the bar code and a wider range of bar code densities. The invention includes improved optics and sensing elements. To provide a wider depth of field the optics associated with the emitter and or the photodetector have two distinct focal points. In the preferred embodiments, the optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived form the scanned bar code. The two channels have differing resolutions. Analysis of the data from the two channels provides a single decoded result. As the working angle and density vary at least one of the resolutions will be appropriate for sensing all or most of the bar coded data. The data from the channel producing a valid result can be used, or if neither channel produces a valid result by itself, data from each channel can be analyzed and valid portions of the data from both channels combined to produce the single decoded result.
摘要:
A range finder for use with a bar code scanner. An image of a scan line is detected by a sensor array. Distance from the scanner to the bar code symbol is determined from the length of the detected scan line image.
摘要:
An optical scanning system is provided for producing a signal representative of a spatial distribution of indicia having different degrees of reflectivity to light, such as a bar code (14). The system includes an optical scanner (12) for scanning beam of light over the spatial distribution of indicia (14) and for producing an electrical signal corresponding to changes in the degree of reflectivity of the indicia. A digitizer (20), responsive to detections in a predetermined characteristic of the produced electrical signal is provided. The digitizer (20) converts the detections into digital words, such digital signals having a plurality of bits. The digitizer includes a timing generation circuit (42) for producing a pulse in response to each one of the detections with a time duration representative of the degree of reflectivity of the indicia as the beam of light. A decoder converts the time duration of the pulse into the digital word having a plurality of bits. An enhancement filter (30) is also disclosed. The enhancement filter (30) modifies pulses produced by a differentiator circuit (24) used in the scanner. Such modification includes increasing the rise time, and peak level of, the pulses produced by the differentiator circuit (24).
摘要:
A scanning device for reading indicia of differing light reflectivity, including bar code or matrix array symbols, has a single light emitter, such as a laser or light emitting diode, for generating a scanning light beam to visually illuminate sequential portions of the indicia. A sensor, such as a charge coupled or other solid state imaging device, simultaneously detects light reflected from portions of the indicia and generates an electrical signal representative of the spacial intensity variations the portions of the indicia. The scanning device may also include an ambient light sensor, and a second light emitter for use only in aiming or orienting the scanning device. A photodetector may also be provided to separately detect one symbol virtually simultaneous with the detection of another symbol by the sensor or to provide dual modalities. A method for reading indicia is also provided.
摘要:
An imaging assembly in an imaging reader for electro-optically reading indicia includes a solid-state imager having an array of image sensors, and a focus control element, such as a liquid imaging lens, having a variable transfer function characteristics for capturing, optically modifying and directing return light from the indicia over a field of view onto the imager for processing into an electrical signal indicative of the indicia during a reading mode of operation; and a controller for controlling the imaging assembly to optically modify the return light in accordance with a known transfer function stored in a memory accessible to the controller during a calibration mode of operation prior to the reading mode.
摘要:
An imaging assembly in an imaging reader for electro-optically reading indicia includes a solid-state imager having an array of image sensors, and a focus control element, such as a liquid imaging lens, having a variable transfer function characteristics for capturing, optically modifying and directing return light from the indicia over a field of view onto the imager for processing into an electrical signal indicative of the indicia during a reading mode of operation; and a controller for controlling the imaging assembly to optically modify the return light in accordance with a known transfer function stored in a memory accessible to the controller during a calibration mode of operation prior to the reading mode.