Imaging apparatus with selectable subsets of photosensors
View Patent ↗An image input scanner includes a linear array of photosensors to record images, such as in a digital copier or facsimile. A subset of the photosensors can be selected, depending on a particular situation, for recording images, while other photosensors are deselected. In this way, recording of “blank” image data, such as would be caused when photosensors in the array are not exposed to a sheet passing relative to the array, is avoided. In one embodiment, the array includes a plurality of local clock drivers, each clock driver controlling image data readout from a subset of photosensors. When a subset of photosensors are selected for a given situation, only the clock drivers associated with the selected photosensors are activated.
1. A photosensitive apparatus, comprising:
a plurality of photosensors forming a linear array, the photosensors being organized in a set of groups of photosensors, each group forming a contiguous block of photosensors along the linear array;
a video output line, for accepting image-related video signals from the photosensors; and
selection means for activating a subset of groups of photosensors so that only the activated subset of groups of photosensors outputs image signals onto the video output line to record an image, thereby activating photosensors along only a contiguous portion of the linear array.
2. The apparatus of claim 1 , the groups of photosensors being arranged as a linear array of photosensors.
3. The apparatus of claim 1 , the selection means including
an enabling control associated with each group of photosensors, the enabling control receiving a code relating to whether the associated group of photosensors is to be activated, and enabling the group of photosensors to output image signals if the associated group of photosensors is to be activated.
4. The apparatus of claim 3 , the enabling control including
address receiving means for receiving a code relating to a subset of groups of photosensors to be activated.
5. The apparatus of claim 3 , the enabling control including
means for determining whether the group of photosensors is within the subset of groups of photosensors to be activated.
6. The apparatus of claim 1 , further comprising
a plurality of local clock drivers, each local clock driver activating a group of photosensors.
7. The apparatus of claim 6 , the selection means including
an enabling control associated with each group of photosensors, the enabling control receiving a code symbolic of whether the associated group of photosensors is to be activated, and enabling the local clock driver associated with the group of photosensors if the associated group of photosensors is to be activated.
8. The apparatus of claim 6 , each group of photosensors having associated therewith
a plurality of shift register stages, each shift register stage being associated with at least one photosensor.
9. The apparatus of claim 8 , further comprising
sequencing means for causing a second local clock driver to begin sequentially activating a plurality of shift register stages within its group of photosensors, as a result of a first local clock driver finishing activating a plurality of shift register stages within its group of photosensors.
10. The apparatus of claim 9 , the sequencing means comprising a flip-flop associated with the first local clock driver, the flip-flop having a set input associated with a first shift register stage in the group of photosensors, and a reset input associated with a last shift register stage in the group of photosensors.
11. An apparatus for recording images from a sheet, comprising:
a linear array of photosensors arranged in a linear array, each photosensor being selectable to output a video signal;
means for moving a sheet relative to the linear array of photosensors; and
selection means for selecting a subset of photosensors in the linear array for recording an image on the sheet, each subset of photosensors forming a contiguous block along the linear array, so that only photosensors forming a contiguous portion of the linear array output video signals.
12. The apparatus of claim 11 , further comprising at least one video output line for accepting image-related video signals from the photosensors; and
the selection means activating a subset of groups of photosensors so that only the activated subset of photosensors outputs image signals onto the video output line to record an image.
13. The apparatus of claim 11 , further comprising
a movable guide member conforming to at least one edge of a sheet moving relative to the linear array of photosensors; and
a position detector for detecting a position of the movable guide member;
the selection means being responsive to the position detector.
14. The apparatus of claim 11 , the linear array of photosensors comprising a set of local clock drivers, each clock driver being operative of a group of photosensors In the linear array; and
the selecting means activating at least a subset of local clock drivers to select a subset of photosensors in the linear array.
15. A photosensitive apparatus, comprising:
a plurality of photosensors, the photosensors being organized in a set of groups of photosensors;
a video output line, for accepting image-related video signals from the photosensors;
selection means for activating a subset of groups of photosensors so that only the activated subset of groups of photosensors outputs image signals onto the video output line to record an image;
a plurality of local clock drivers, each local clock driver activating a group of photosensors;
a plurality of shift register stages, each shift register stage being associated with at least one photosensor; and
sequencing means for causing a second local clock driver to begin sequentially activating a plurality of shift register stages within its group of photosensors, as a result of a first local clock driver finishing activating a plurality of shift register stages within its group of photosensors,
the sequencing means comprising a flip-flop associated with the first local clock driver, the flip-flop having a set input associated with a first shift register stage in the group of photosensors, and a reset input associated with a last shift register stage in the group of photosensors.