US 5,847,846 A · Apparatus and method for scanning a bound color document using a wedge shaped platen

Abstract

A color scanner with a wedge shaped platen sequentially records opposing pages of a bound document positioned thereon using a single imaging station. The scanner includes a partially reflective mirror positioned between the wedge shaped platen. The two sides of the wedge shaped platen are illuminated with polarized light having angles orthogonal to each other. Polarized illuminators operate in combination with polarization analyzers positioned under the wedge shaped platen to sequentially image the opposing pages of the bound document. A controller insures that polarized light sources consisting of the three primary colors red, green, and blue, sequentially expose each opposing page of the bound document. The opposing pages of the bound document are focused through optics onto the single imaging station. In another embodiment, light polarized by analyzers positioned under the wedge shaped platen is filtered by a polarizer positioned in front of the focal optics before reaching the single imaging station. The controller first exposes one side of the platen and then the other to each of the three primary colors red, green, and blue. Digital representations of each primary color are combined to form a single composite image for each opposing page of the bound document. In one arrangement, the imaging station is a two-dimensional array of detectors which sense an image of a page of the bound document projected thereon. In another arrangement, the imaging station is a photoconductive belt which when exposed by the polarized light records a latent image thereon. In either arrangement, a one page imaging station records opposing pages of a bound document either electronically or on print media, one page at a time.

Claims29

Dependent claims

An apparatus for scanning a bound document, comprising:

a wedge shaped platen having a first transparent surface and a second transparent surface for supporting the bound document in an open condition;
a light source for illuminating a first opposing page and a second opposing page of the bound document positioned on the first and the second transparent surfaces of said wedge shaped platen;
a first polarizer for polarizing light emitted by said light source to illuminate the first opposing page with light polarized at a first angle;
a second polarizer for polarizing light emitted by said light source to illuminate the second opposing page with light polarized at a second angle;
an imager for recording the first and the second opposing pages of the bound document on said wedge shaped platen one page at a time;
and
a beamsplitter positioned in a defined transmissive optical path between the first transparent surface and said imager, and a defined reflective optical path from the second transparent surface and said imager, said beamsplitter transmitting onto said imager light polarized at the first angle and reflecting onto said imager light polarized at the second angle.

4 more elements

Dependencies are inferred from the claim text.

Apparatus and method for scanning a bound color document using a wedge shaped platen

Life of this patent

Apparatus and method for scanning a bound color document using a wedge shaped platen

Life of this patent

Abstract

Claims29