Motion detection image sensors and methods for controlling a motion detection image sensor

1. An image sensor comprising:

a plurality of pixel cells, each pixel cell configured to convert incident light to an electric signal indicating the intensity of the incident light;

a pixel determination circuit configured to determine a pixel cell of the plurality of pixel cells based on light incident to the plurality of pixel cells; and

an output circuit configured to output the electrical signal of the determined cell;

wherein each pixel cell comprises:

a photo detector configured to convert incident light to an electric signal indicating the intensity of the incident light;

a criterion determination circuit configured to determine whether the incident light fulfills a pre-determined criterion; and

an indication circuit configured to transmit an indication indicating that the incident light fulfills the pre-determined criterion if the incident light fulfills the pre-determined criterion;

wherein the criterion determination circuit comprises a light change detector; and

wherein the criterion determination circuit comprises a high-pass filter configured to filter an output of the light change detector;

wherein the light change detector is an electrical circuit configured to generate an electrical signal based on the change in the output current of the photo detector.

2. The image sensor of claim 1 , wherein the criterion determination circuit further comprises a tunable high-pass filter.

3. The image sensor of claim 2 , wherein each pixel cell further comprises a cut-off frequency input line configured to receive information indicating a cut-off frequency of the high-pass filter.

4. The image sensor of claim 1 , wherein the criterion determination circuit further comprises a comparator.

5. The image sensor of claim 4 , wherein the indication circuit is further configured to transmit a signal indicating that the incident light fulfills the pre-determined criterion if the output of the high-pass filter is higher than the pre-determined comparator threshold.

6. The image sensor of claim 4 , wherein the comparator is configured to compare an output of the high-pass filter with a pre-determined comparator threshold.

7. The image sensor of claim 6 , wherein each pixel cell further comprises a comparator threshold input line configured to receive information indicating the comparator threshold.

8. The image sensor of claim 1 , wherein the pixel determination circuit is further configured to determine the pixel cell of the plurality of pixel cells as a pixel cell for which the light incident to the pixel cell fulfills a pre-determined criterion.

9. The image sensor of claim 8 , wherein the pixel determination circuit further comprises:

a row arbiter configured to process a row of pixel cells in which at least one pixel cell fulfills the pre-determined criterion.

10. The image sensor of claim 8 , wherein the pixel determination circuit further comprises:

a column arbiter configured to process a column of pixel cells in which at least one pixel cell fulfills the pre-determined criterion.

11. A method for controlling an image sensor, the method comprising:

controlling a plurality of pixel cells, each pixel cell converting incident light to an electric signal indicating the intensity of the incident light;

determining a pixel cell of the plurality of pixel cells based on light incident to the plurality of pixel cells; and

outputting the electrical signal of the determined cell;

wherein controlling of each pixel cell comprises:

converting incident light to an electric signal indicating the intensity of the incident light;

determining whether the incident light fulfills a pre-determined criterion; and

transmitting an indication indicating that the incident light fulfills the pre-determined criterion if the incident light fulfills the pre-determined criterion;

wherein the determining whether the incident light fulfills a pre-determined criterion comprises detecting a light change, using a light change detector, of the incident light; and

wherein the determining whether the incident light fulfills a pre-determined criterion comprises high-pass filtering a detected light change signal;

wherein the light change detector is an electrical circuit configured to generate an electrical signal based on the change in the output current of the photo detector.

12. The method of claim 11 , wherein the high-pass filtering comprises using a tunable high-pass filter.

13. The method of claim 12 , wherein controlling of each pixel cell further comprises:

receiving information indicating a cut-off frequency of the high-pass filter.

14. The method of claim 11 , wherein the determining whether the incident light fulfills a pre-determined criterion further comprises using a comparator.

15. The method of claim 14 , wherein transmitting the indication further comprises transmitting a signal indicating that the incident light fulfills the pre-determined criterion if the output of the high-pass filtering is higher than the pre-determined comparator threshold.

16. The method of claim 14 , wherein the determining whether the incident light fulfills a pre-determined criterion further comprises comparing an output of the high-pass filtered signal with a pre-determined comparator threshold.

17. The method of claim 16 , wherein controlling of each pixel cell further comprises:

receiving information indicating the comparator threshold.

18. The method of claim 11 , wherein determining the pixel cell of the plurality of pixel cells comprises determining the pixel cell of the plurality of pixel cells as a pixel cell for which the light incident to the pixel cell fulfills a pre-determined criterion.

19. The method of claim 18 , wherein determining the pixel cell of the plurality of pixel cells comprises processing a row of pixel cells in which at least one pixel cell fulfills the pre-determined criterion.

20. The method of claim 18 , wherein determining the pixel cell of the plurality of pixel cells comprises processing a column of pixel cells in which at least one pixel cell fulfills the pre-determined criterion.