Expanded image sensor pixel array
An image sensor may be implemented by mounting a first die to a second die. The first die may include an image sensor pixel array having active pixels and non-active pixels, while the second die may include pixel control and readout circuitry that are coupled to the image sensor pixel array via inter-die connections. The image sensor pixel array may have pixel columns in excess of corresponding column readout paths in the pixel readout circuitry and/or pixel rows in excess of corresponding sets of row control paths in the pixel control circuitry. A select set of inter-die connections may be implemented to provide connections between a desired set of pixel columns and the limited number of column readout paths and to provide connections between a desired set of pixel rows and the limited number of sets of row control paths.
1. An image sensor comprising:
a first integrated circuit die including an image sensor pixel array having active pixels and non-active pixels arranged in a number of pixel columns; and
a second integrated circuit die mounted to the first integrated circuit die, the second integrated circuit die including pixel readout circuitry having a number of readout paths fewer than the number of pixel columns, wherein a first set of the pixel columns in the image sensor pixel array are coupled to the readout paths in the pixel readout circuitry via column lines, the first set of pixel columns including first non-active pixels coupled to at least some of the readout paths in the pixel readout circuitry, and wherein a second set of the pixel columns in the image sensor pixel array are decoupled from the pixel readout circuitry, the second set of pixel columns including second non-active pixels decoupled from the pixel readout circuitry.
2. The image sensor defined in claim 1 , wherein the first and second integrated circuit dies include respective interconnect structures for forming inter-die connections, and the column lines are implemented using the inter-die connections.
3. The image sensor defined in claim 2 , wherein inter-die connections for the second set of the pixel columns are at least partly absent.
4. The image sensor defined in claim 1 , wherein the non-active pixels in the image sensor pixel array comprise an optically black pixel configured to generate a reference signal indicative of a noise level.
5. The image sensor defined in claim 1 , wherein the first non-active pixels include an optically black pixel.
6. The image sensor defined in claim 1 , wherein the second non-active pixels include an optically black pixel.
7. The image sensor defined in claim 1 , wherein the non-active pixels in the image sensor pixel array comprise an electrically black pixel configured to generate a reference signal indicative of a noise level.
8. The image sensor defined in claim 1 , wherein the first non-active pixels include an electrically black pixel.
9. The image sensor defined in claim 1 , wherein the second non-active pixels include an electrically black pixel.
10. The image sensor defined in claim 1 , wherein the active pixels are arranged in a central portion of the image sensor pixel array, and the non-active pixels are arranged in a peripheral portion of the image sensor pixel array.
11. The image sensor defined in claim 10 , wherein the second set of the pixel columns comprises the active pixels in the central portion of the image sensor pixel array.
12. The image sensor defined in claim 10 , wherein the first set of the pixel columns comprises the active pixels in the central portion of the image sensor pixel array.
13. The image sensor defined in claim 1 , wherein the first integrated circuit die and the second integrated circuit die are implemented as stitched dies.
14. The image sensor defined in claim 1 , wherein the first non-active pixels comprise first buffer pixels and first reference pixels and wherein the second non-active pixels comprise second buffer pixels and second reference pixels.
15. An image sensor comprising:
a first integrated circuit die including an image sensor pixel array having active pixels and non-active pixels arranged in a number of pixel rows; and
a second integrated circuit die mounted to the first integrated circuit die, the second integrated circuit die including pixel control circuitry having a number of sets of control paths fewer than the number of pixel rows, wherein a first set of the pixel rows in the image sensor pixel array are coupled to the set of control paths in the pixel control circuitry via row lines and a second set of the pixel rows in the image sensor pixel array are decoupled from the pixel control circuitry, wherein the first integrated circuit die is a stitched die constructed by a step and repeat exposure process using a reticle set.
16. The image sensor defined in claim 15 , wherein the first and second integrated circuit dies include respective interconnect structures for forming inter-die connections, and the row lines are implemented using the inter-die connections.
17. The image sensor defined in claim 16 , wherein inter-die connections for the second set of the pixel rows are at least partly absent.
18. An image sensor comprising:
an array of image sensor pixels; and
a circuitry block coupled to the array of image sensor pixels via a set of parallel conductive lines, each conductive line being coupled to a corresponding set of image sensor pixels in the array of image sensor pixels, wherein the array of image sensor pixels includes a set of redundant pixels that are decoupled from the circuitry block and wherein the set of redundant pixels comprises active pixels.
19. The image sensor defined in claim 18 , wherein the array of image sensor pixels is implemented on a first integrated circuit die, and the circuitry block is implemented on a second integrated circuit die mounted to the first integrated circuit die.
20. The image sensor defined in claim 19 , wherein the set of redundant pixels comprises non-active pixels.