CCD sensors with multiple contact patterns
View Patent ↗A pixel array in an image sensor includes multiple pixels. The pixel array includes vertical shift registers for shifting charge out of the pixel array. The vertical shift registers can be interspersed between the pixels, such as in an interline image sensor, or the photosensitive areas in the pixels can operate as vertical shift registers. The pixels are divided into blocks of pixels. One or more electrodes are disposed over each pixel. Conductive strips are disposed over the electrodes. Contacts are used to connect selected electrodes to respective conductive strips. The contacts in at least one block of pixels are positioned according to one contact pattern while the contacts in one or more other blocks are positioned according to a different contact pattern. The different contact patterns reduce or eliminate visible patterns in the contact locations.
1. An image sensor comprising: a pixel array divided into a plurality of blocks of pixels with each block including two or more pixels, the pixel array including a plurality of vertical shift registers for shifting charge out of the pixel array; one or more electrodes disposed over each pixel; a plurality of conductive strips disposed over the electrodes; and a first plurality of contacts connecting selected electrodes to respective conductive strips of the plurality of the conductive strips, wherein the contacts in at least one block of pixels are positioned according to one contact pattern and the contacts in one or more other blocks of pixels are positioned according to a different contact pattern.
2. The image sensor as in claim 1 , further comprising a second plurality of contacts connecting at least one end of each of the electrodes to one or more bus lines.
3. The image sensor as in claim 1 , wherein the image sensor is implemented as one of a frame transfer CCD image sensor, an interline CCD image sensor, or a full frame CCD image sensor.
4. The image sensor as in claim 1 , wherein the conductive strips comprise metal strips.
5. The image sensor as in claim 1 , wherein the electrodes comprise polysilicon electrodes.
6. The image sensor as in claim 1 , further comprising conductive strips connecting at least one end of selected electrodes to respective bus lines.
7. The image sensor as in claim 1 , further comprising at least one horizontal shift register for receiving charge from at least some of the vertical shift registers.
8. The image sensor as in claim 1 , wherein each of the plurality of conductive strips extends vertically across the entire pixel array.
9. The image sensor as in claim 1 , wherein each of the plurality of conductive strips extends vertically over only a portion of the pixel array.
10. The image sensor as in claim 1 , wherein each block of pixels comprises at least 16pixels.
11. The image sensor as in claim 1 , wherein each block of pixels comprises at least 25pixels.
12. The image sensor as in claim 1 , wherein each of the one or more electrodes extends linearly across a plurality of pixels.
13. The image sensor as in claim 12 , wherein each of the plurality of the conductive strips extends linearly across the one or more electrodes of each pixel.
14. The image sensor as in claim 13 , wherein the conductive strips of the plurality of the conductive strips and one or more electrodes are approximately perpendicular to each other.