Image scanner with optical waveguide and enhanced optical sampling rate

Abstract

An optical waveguide and a shutter are used to guide light from multiple illuminated pixels on a document being scanned onto a single photosensor element. Various methods are disclosed for selecting one pixel at a time for projection onto a single sensor element. Multiple scans are required to capture all the image pixels. The data from multiple scans are then combined to form a single scanned image that has a higher optical sampling rate than the native optical sampling rate of the sensor array. Superresolution image analysis techniques developed for reconstruction of one image from a set of lower resolution images may be applied to provide a diffraction-limited high-resolution image. The waveguide as described also provides an ability to reduce scanning time for lower resolution images. In a first example embodiment, a rotating rod lens with a pattern of black and white areas is used to block/unblock optical waveguide array elements. In a second example embodiment, a thin mask is translated over the optical waveguide array elements. In a third example embodiment, an electronic display device such as a liquid crystal array is used to block/unblock optical waveguide array elements.