Photosensor architecture for a color raster input scanner
View Patent ↗In an image sensor array, as would be used in an input scanner such as in a digital copier, an original image is moved relative to a linear array of photosites. Each photosite includes at least two wide photosensors, each of which extends substantially across the photosite along the array direction, and at least two narrow photosensors, which are arranged next to each other along the array direction. In one embodiment, the wide photosensors include primary-color filters and the narrow photosensors are clear-filtered.
1. An image sensor array, comprising:
a linear array of photosites, the linear array extending along an array direction,
each photosite including at least two wide photosensors and at least two narrow photosensors, each wide photosensor extending substantially across a width of the photosensor site along the array direction, the narrow photosensors being arranged within the photosite along the array direction;
each of the wide photosensors having a switch associated therewith, the switch of each wide photosensor being disposed proximate to the wide photosensor, each of the wide photosensors in a photosite being associated with a common transfer circuit; and
each of the narrow photosensors being associated with a transfer circuit.
2. The image sensor array of claim 1 , each of at least two of the wide photosensors being sensitive to a predetermined color.
3. The image sensor array of claim 1 , each of at least two of the wide photosensors having associated therewith a translucent filter.
4. The image sensor array of claim 1 , wherein there are three wide photosensors, each wide photosensor being sensitive to a predetermined primary color of the visible spectrum.
5. The image sensor array of claim 4 , each of the narrow photosensors being substantially clear with regard to the visible spectrum.
6. The image sensor array of claim 1 , each of the wide photosensors including a photodiode.
7. The image sensor array of claim 1 , the switch associated with each wide photosensor comprising a semiconductor device operating in a linear region.
8. The image sensor array of claim 1 , the transfer circuit associated with each narrow photosensor including means for accepting a fat zero charge.
9. The image sensor array of claim 1 , each of the wide photosensors having a switch associated therewith.
10. The image sensor array of claim 1 , the common transfer circuit including means for accepting a fat zero charge.
11. The image sensor array of claim 9 , the switch comprising a semiconductor device operating in a linear region.
12. The image sensor array of claim 9 , wherein a capacitance associated with each wide photosensor is substantially equal to a capacitance associated with each narrow photosensor.
13. An image sensor array, comprising a plurality of photosites for receiving light, each photosite having associated therewith:
at least two photosensors of a first type;
a bucket-brigade transfer circuit associated with each photosensor of the first type;
at least two photosensors of a second type;
a switch associated with each photosensor of the second type;
an intermediate node for receiving signals from the switches;
a bucket-brigade transfer circuit associated with the intermediate node; and
a common node for receiving signals from the bucket-brigade transfer circuits.
14. The image sensor array of claim 13 , each switch comprising a semiconductor device operating in a linear region.
15. The image sensor array of claim 13 , further comprising a switch interposed between each bucket-brigade transfer circuit and the common node.
16. The image sensor array of claim 13 , wherein at least one of the photosensors of the second type is associated with a primary-color filter.
17. The image sensor array of claim 13 , wherein each photosensor of the second type is associated with a primary-color filter, and each photosensor of the first type is effectively unfiltered.
18. The image sensor array of claim 13 , wherein each photosensor of the second type is relatively wide with respect to an array direction, and each photosensor of the first type is relatively narrow with respect to the array direction.