Image sensor and imaging device

Abstract

In an image sensor in which a photoelectric conversion film and a readout circuit that reads out the charge generated by the photoelectric conversion film are stacked, readout noise is reduced. [Solution] The image sensor comprises a photoelectric conversion unit 31 that converts light into electric charge, a storage unit 33 in which the charge from the photoelectric conversion unit is stored, a transfer path 34 that transfers charge from the photoelectric conversion unit to the storage unit and has a potential lower than the pixel separation region formed around the photoelectric conversion unit, and a measuring unit that measures the number of times a predetermined amount of charge has been stored in the storage unit and measures the amount of charge stored in the photoelectric conversion unit.

Claims

1. A photoelectric conversion unit that converts light into electric charge, A conversion unit that converts a first signal based on the charge converted by the photoelectric conversion unit during a first period and a second signal based on the charge converted by the photoelectric conversion unit during a second period different from the first period into digital signals in different ways, A recording unit records identification information for distinguishing between a first digital signal converted from the first signal to a digital signal by the conversion unit and a second digital signal converted from the second signal to a digital signal by the conversion unit. An image sensor equipped with the following features.

2. In the image sensor according to claim 1, The recording unit is an image sensor that records the first digital signal and the second signal together with the identification information.

3. In the image sensor according to claim 2, The conversion unit is an image sensor that converts the first signal into the first digital signal using a first conversion method, and converts the second signal into the second digital signal using a second conversion method different from the first conversion method.

4. In the image sensor according to claim 3, The conversion unit is an image sensor having a first terminal to which a signal based on the charge converted by the photoelectric conversion unit is input, a second terminal to which a reference signal for converting the signal based on the charge converted by the photoelectric conversion unit into a digital signal is input, and a third terminal to which the comparison result between the signal based on the charge converted by the photoelectric conversion unit and the reference signal is output.

5. In the image sensor according to claim 4, The conversion unit is an image sensor to which a predetermined value is input as the reference signal in the first conversion method and a changing value is input as the reference signal in the second conversion method.

6. In the image sensor according to claim 5, The conversion unit is an image sensor to which, in the first conversion method, a constant value is input to the second terminal as the reference signal, and in the second conversion method, a value that changes according to the elapsed time is input to the second terminal as the reference signal.

7. In the image sensor according to claim 6, The conversion unit is an image sensor that, in the first conversion method, outputs a signal as a first digital signal based on the number of times the signal value of the charge converted by the photoelectric conversion unit exceeds the signal value of the reference signal.

8. In the image sensor according to claim 7, The conversion unit is an image sensor that, in the second conversion method, outputs a signal as the second digital signal based on the time it takes for the signal value of the reference signal to exceed the signal value of the charge-based signal converted by the photoelectric conversion unit.

9. In the image sensor according to claim 8, The image sensor wherein the second period is a period later than the first period.

10. In the image sensor according to claim 9, The first period and the second period are within a single frame period of the image sensor.

11. In the image sensor according to claim 10, The identification information is an image sensor having information indicating that the first digital signal has been converted by the first conversion method.

12. In the image sensor according to claim 11, The identification information is an image sensor having information indicating that the second digital signal has been converted by the second conversion method.

13. In the image sensor according to claim 3, The conversion unit is an image sensor that, in one frame period, converts a signal based on charge converted by the photoelectric conversion unit using the first conversion method into a digital signal, and then converts the signal based on charge converted by the photoelectric conversion unit into a digital signal using the second conversion method.

14. In the image sensor according to claim 13, The system includes a control unit that outputs information based on the conversion method of the conversion unit to the recording unit, The recording unit is an image sensor that records information based on the conversion method of the conversion unit output by the control unit as the identification information.

15. In the image sensor according to claim 14, The aforementioned identification information is an image sensor used to identify which conversion method was used to convert the digital signal recorded in the recording unit.

16. In the image sensor according to claim 15, An image sensor comprising a calculation unit that adds the first digital signal and the second digital signal.

17. In the image sensor according to claim 16, The calculation unit is an image sensor that adds the first digital signal and the second digital signal using the identification information.

18. In the image sensor according to claim 17, The calculation unit is an image sensor that performs signal processing on the first digital signal and the second digital signal based on the identification information.

19. In the image sensor according to claim 18, The calculation unit is an image sensor that performs a conversion process to add the first digital signal and the second digital signal as part of the signal processing.

20. In the image sensor according to claim 18, The calculation unit is an image sensor that performs the signal processing on the first digital signal and the second digital signal output from the recording unit.

21. The image sensor according to claim 15, An imaging device comprising a calculation unit that adds the first digital signal and the second digital signal.

22. In the imaging device according to claim 21, The calculation unit is an imaging device that adds the first digital signal and the second digital signal using the identification information.

23. In the imaging device according to claim 21, The calculation unit is an imaging device that performs signal processing on the first digital signal and the second digital signal based on the identification information.

24. In the imaging device according to claim 23, The calculation unit is an imaging device that performs a conversion process to add the first digital signal and the second digital signal as part of the signal processing.

25. In the image sensor according to claim 3, A storage unit where charge from the photoelectric conversion unit is accumulated, The system includes a transfer path that transfers charge from the photoelectric conversion unit to the storage unit, The transfer path portion is an image sensor with a lower potential than the region formed around the photoelectric conversion portion.

26. In the image sensor according to claim 25, The transfer path portion is an image sensor with a lower potential than the pixel separation region formed around the photoelectric conversion portion.

27. In the image sensor according to claim 26, The transfer path portion is formed with an image sensor having a lower impurity concentration than the pixel separation region.

28. In the image sensor according to claim 3, A first semiconductor substrate having the aforementioned photoelectric conversion unit, An image sensor comprising a substrate stacked together with the first semiconductor substrate, the second semiconductor substrate having the recording portion.

29. In the image sensor according to claim 28, The photoelectric conversion unit is an image sensor positioned opposite the recording unit in the stacking direction in which the first semiconductor substrate and the second semiconductor substrate are stacked.

30. In the image sensor according to claim 28, The second semiconductor substrate is an image sensor having the conversion unit.

31. In the image sensor according to claim 30, The photoelectric conversion unit is an image sensor positioned opposite to the conversion unit in the stacking direction in which the first semiconductor substrate and the second semiconductor substrate are stacked.

32. In the image sensor according to claim 28, An image sensor capable of independently controlling the potential of the first semiconductor substrate and the potential of the second semiconductor substrate.

33. In the image sensor according to claim 32, The first semiconductor substrate has a first grounding portion for setting the ground potential of the first semiconductor substrate, The second semiconductor substrate is an image sensor having a second grounding portion for setting the ground potential of the second semiconductor substrate.

34. In the image sensor described in claim 31 The first semiconductor substrate has a first power line that supplies electricity to the first semiconductor substrate, The second semiconductor substrate is an image sensor having a second power line for supplying electricity to the second semiconductor substrate.

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