초록 ▼

An improved sensor array and illumination scheme for a bar code scanner use a modified Scheimpflug arrangement optical system that simplifies signal processing. The preferred embodiment includes a detector array comprising a multi-element array of photosensors positioned in one Scheimpflug plane and

An improved sensor array and illumination scheme for a bar code scanner use a modified Scheimpflug arrangement optical system that simplifies signal processing. The preferred embodiment includes a detector array comprising a multi-element array of photosensors positioned in one Scheimpflug plane and an illumination beam in the form of a sheet of light along the other Scheimpflug plane. The detector array has a plurality of elements having a long axis and a short axis, with the long axis of the elements arranged substantially perpendicular to the image of the illuminated strip of the bar code tag. The projection of the long axis of the elements of the array onto the other Scheimpflug plane defines the working range of the optical system. So long as the bar code tag intersects the illumination beam within the working range, the image of the illuminated strip of the bar code tag will be substantially in focus across the elements of the detector array. Filtering allows substantially only the light from the illuminated strip to reach the detector array. Thus, substantially all of the light that reaches the detector array is useful signal, and all the output data from the array during a bar code scan is relevant. The output signal from the array can be processed with conventional digitizing and decoding circuitry with audio signal processing techniques.

대표청구항 ▼

An optical system for a bar code scanner for reading a bar code tag, comprising: a focusing means having an optical axis; illumination means for projecting a sheet of light along an object plane at a first acute angle with respect to a plane perpendicular to the optical axis of the focusing means, f

An optical system for a bar code scanner for reading a bar code tag, comprising: a focusing means having an optical axis; illumination means for projecting a sheet of light along an object plane at a first acute angle with respect to a plane perpendicular to the optical axis of the focusing means, for illuminating a strip on the bar code tag to be read; and a detector array for receiving light reflected from the bar code tag, with a plurality of elements having a long axis and a short axis, positioned substantially in an image plane at a second acute angle with respect to a plane perpendicular to the optical axis of the focusing means, with the long axis of the elements arranged substantially perpendicular to the image of the illuminated strip of the bar code tag, the projection of the long axis of the elements of the detector array onto the object plane defining the working range of the optical system; a plane through the focusing means perpendicular to the optical axis of the focusing means, the image plane and the object plane all intersecting along a line so that an image of the illuminated strip of the bar code tag is formed substantially in focus on the detector array when the bar code tag is within the working range of the optical system.