Method and apparatus for contact image scanning
View Patent ↗A contact image scanner comprises a light source, pixel sensors generating a signal, a lens focusing reflected light onto the pixel sensors, a color matrix filter filtering the reflected light, and a signal processing circuit generating a digital image. The method provides pixel sensors for generating a signal in response to incident light, projects light from a light source onto a document in a sequential fashion, reflects the light onto the pixel sensors, filters the reflected light with a color matrix filter, and processes the signal to generate the digital image. With the method and apparatus, each scan line of the document is illuminated with white light only once. The pixel sensors corresponding to red, green, and blue colors of each pixel of the scan line read the pixel of the scan line substantially at the same time in a substantially overlapping manner in a scan line direction without overlapping in an orthogonal direction.
1. An imaging apparatus for creating a digital image of a document, comprising:
a light source for illuminating a scan line of said document, the scan line comprising a plurality of pixels;
a plurality of pixel sensors for generating a plurality of signals in response to light incident thereon;
a lens for focusing light from said light source reflected from said plurality of pixels of said scan line of said document onto said plurality of pixel sensors;
a color matrix filter disposed between said pixel sensors and said lens for filtering said reflected light from each pixel in the plurality of pixels of said scan line of said document into a plurality of colors prior to said reflected light being incident at said plurality of pixel sensors; and
a circuit for processing said generated plurality of signals representative of said plurality of colors of said reflected light incident on said plurality of pixel sensors to generate said digital image of said document;
wherein each scan line of said document is illuminated only once such that the plurality of pixel sensors corresponding to the plurality of colors of each pixel of said scan line of said document read said pixel of said scan line substantially at the same time in substantially overlapping manner in a scan line direction without overlapping in a direction orthogonal to said scan line direction.
2. The apparatus of claim 1 , wherein said color matrix filter is a Bayer pattern color matrix filter.
3. The apparatus of claim 1 , wherein said color matrix filter comprises an RGB pattern color matrix filter.
4. The apparatus of claim 3 , wherein said color matrix filter is disposed adjacent said pixel sensors.
5. The apparatus of claim 1 , wherein said lens comprises an array of rod lenses.
6. The apparatus of claim 1 , wherein said plurality of pixel sensors comprises an array of pixel sensors.
7. The apparatus of claim 6 , wherein said color matrix filter is formed integrally with said array of pixel sensors.
8. The apparatus of claim 6 , wherein said array of pixel sensors supplies a plurality of analog data signals to said circuit.
9. The apparatus of claim 8 , wherein said circuit includes an analog to digital converter for converting said plurality of analog data signals to a plurality of digital data signals.
10. The apparatus of claim 9 , wherein said circuit includes a multiplexing circuit for multiplexing said plurality of digital data signals into a plurality of color channel signals.
11. The apparatus of claim 10 , wherein said multiplexing circuit multiplexes said plurality of digital data signals into red, green, and blue color channel signals.
12. The apparatus of claim 10 , wherein said circuit includes a memory for storing said plurality of color channel signals.
13. The apparatus of claim 1 , wherein said light source illuminates said document with white light.
14. A method of creating a digital image of a document having a length dimension, comprising:
providing a plurality of pixel sensors for generating a plurality of signals in response to light incident thereon;
projecting light from a light source onto said document in a sequential fashion along the length dimension thereof thereby illuminating a plurality of scan lines, each of said plurality of scan lines comprising a plurality of pixels;
reflecting said light projected onto said plurality of pixels of each scan line of said document onto said plurality of pixel sensors;
filtering said reflected light from each pixel in said plurality of pixels of each scan line of said document into a plurality of colors prior to said reflected light being incident at said plurality of pixel sensors; and
processing said generated plurality of signals representative of said plurality of colors of said reflected light incident on said plurality of pixel sensors to generate said digital image of said document;
wherein each scan line of said document is illuminated only once such that the plurality of pixel sensors corresponding to the plurality of colors of each pixel of each scan line of said document read said pixel of each scan line substantially at the same time in substantially overlapping manner in a scan line direction without overlapping in a direction orthogonal to said scan line direction.
15. The method of claim 14 , wherein said filtering said light comprises filtering said light with a Bayer color matrix filter.
16. The method of claim 14 , wherein said filtering said light comprises filtering said light with a color matrix filter of RGB.
17. An image scanner for scanning a document comprising:
a light source for illuminating a scan line of said document with white light, the scan line comprising a plurality of pixels;
a plurality of pixel sensors for generating a plurality of signals in response to light incident thereon;
a lens for focusing light from said light source reflected from said plurality of pixels of said scan line of said document onto said plurality of pixel sensors;
a color matrix filter disposed between said pixel sensors and said lens for filtering said reflected light from each pixel in the plurality of pixels of said scan line of said document into a plurality of colors prior to said reflected light being incident at said plurality of pixel sensors, said plurality of colors comprising red, green and blue; and
a circuit for processing said plurality of signals representative of said plurality of red green and blue colors of said reflected light incident on said plurality of pixel sensors to generate a digital image of said document;
wherein each scan line of said document is illuminated with said white light only once such that the plurality of pixel sensors corresponding to said red, green, and blue colors of each pixel of said scan line of said document read said pixel of said scan line substantially at the same time in substantially overlapping manner in a scan line direction without overlapping in a direction orthogonal to said scan line direction.
18. The image scanner of claim 17 , wherein said color matrix filter is a Bayer pattern color matrix filter.
19. The image scanner of claim 17 , wherein said color matrix filter is disposed adjacent said pixel sensors.