Document scanner

摘要

A document scanner comprises a first image sensor unit (32) and a second image sensor unit (30) and a scanning mechanism (70, 72, 76, 80) for causing relative movement between a document and the units so that the units scan the document in a scanning direction. The first unit (32) is situated ahead of the second unit (30) in the scanning direction and partially overlaps the second unit. Each sensor unit has a respective linear array (44) of electromagnetic radiation detectors and one or more light guides (48, 49) for directing light from a respective one of two imaging lines (63) on to the detectors, wherein, in use, the imaging lines scan the document to capture data representative of two respective sets of scan line portions for combination to obtain a succession of scan lines for the document, the one or more light guides of the first unit (32) are angled rearwardly with respect to the scanning direction, whilst the one or more light guides of the second unit (30) are angled forwardly with respect to the scanning direction, so as to reduce the distance with respect to the scanning direction, between the imaging lines (63).

主权项

1. A document scanner comprising a first image sensor unit and a second image sensor unit and a scanning mechanism for causing relative movement between a document and the image sensor units so that the image sensor units scan the document in a scanning direction, the first image sensor unit being situated ahead of the second image sensor unit in the scanning direction and partially overlapping the second image sensor unit, each image sensor unit having a respective linear array of electromagnetic radiation detectors and one or more light guides for directing light from a respective one of two imaging lines on to the linear array of electromagnetic radiation detectors, wherein, in use, the imaging lines scan the document to capture data representative of two respective sets of scan line portions for combination to obtain a succession of scan lines for the document, the one or more light guides of the first image sensor unit being angled rearwardly with respect to the scanning direction, whilst the one or more light guides of the second image sensor unit are angled forwardly with respect to the scanning direction, wherein the one or more light guides for each image sensor unit comprises a respective linear array of light guides, each light guide directing light from a respective imaging point to a respective electromagnetic radiation detector, the imaging points defining the imaging lines, and wherein the linear arrays of electromagnetic radiation detectors and the linear arrays of light guides of each image sensor unit are offset towards a closer edge of that image sensor unit, the image sensor units being arranged with the closer edges adjacent to each other.