Abstract: A multi-channel scanner having several photodetectors (12a-12d) and several lasers (10a-10d) for scanning along multiple paths (50a-50d) incorporates a separate input channel (26a-26d) for each photodetector. Each channel provides a sequence of data elements representing light reflected from points along the associated scanning path, and the data elements from each channel are stored in separate FIFO buffers (20a-20d). A multiplexer (22) takes data elements from the various buffers so as from a consolidated stream of data elements (80) incoporating the data elements from the various channels. This stream is processed in a single decoder (24) to recover data denoted by the bar code. Use of a single decoder minimizes the cost and size of the system.

Abstract: One aspect of the invention provide a scanner for scanning objects bearing codes such as bar codes. A scanner according to this aspect of the invention desirably includes a plurality of input channels, each said channel including a photodetector. Each input channel is arranged to provide data elements representing light impinging on the photodetector of such channel. The scanner also includes means for exposing the photodetectors of said channels to light from objects to be scanned so that the light impinging on the photodetector of each channel represents an optical property of objects to be scanned at a series of points along a scanning path associated with such channel. As in a conventional scanner, the means for exposing most typically includes one or more light sources such as one or more lasers, together with optical elements for forming the emitted light from the sources into a plurality of scanning beams, each focused at a spot, and for moving the spot of each beam along a scanning path.