Imaging device and imaging system
An imaging device includes pixels each including first and second photoelectric conversion units on which pupil-divided parts of incident light are incident and a holding unit that holds charges transferred from the first and second photoelectric conversion units, and outputting signals based on amounts of charges held by the holding unit. Each pixel outputs a first signal and a second signal based on amounts of charges generated by the first photoelectric conversion unit and by the first and second photoelectric conversion units, respectively, during a first exposure time, and a third signal and a fourth signal based on amounts of charges generated by the first photoelectric conversion unit and by the first and second photoelectric conversion units, respectively, during a second exposure time. The first and second signals are output before the third and fourth signals in one frame and after the third and fourth signals in another frame.
1. An imaging device comprising:
a plurality of pixels each including a first photoelectric conversion unit on which a first part of pupil-divided incident light is incident; a second photoelectric conversion unit on which a second part of the pupil-divided incident light is incident; a first holding unit that holds charges transferred from the first photoelectric conversion unit and the second photoelectric conversion unit; and an amplifier unit that outputs a signal based on an amount of the charges held by the first holding unit, wherein
each of the plurality of pixels is configured to output a first signal based on an amount of charges generated by the first photoelectric conversion unit during a first exposure time, a second signal based on an amount of charges generated by the first photoelectric conversion unit and the second photoelectric conversion unit during the first exposure time, a third signal based on an amount of charges generated by the first photoelectric conversion unit during a second exposure time, which is shorter than the first exposure time, and a fourth signal based on an amount of charges generated by the first photoelectric conversion unit and the second photoelectric conversion unit during the second exposure time, and
in a certain one of frames, the first and second signals are output before the third and fourth signals, and in another one of the frames, the first and second signals are output after the third and fourth signals.
2. The imaging device according to claim 1 , wherein
an interval between a timing to output the first signal and a timing to output the third signal is different between the frames.
3. The imaging device according to claim 2 , wherein
in the frame in which the third and fourth signals are output before the first and second signals, an interval between a timing to output the third signal and a timing to output the first signal is longer than a half period of the frame.
4. The imaging device according to claim 1 , wherein
each of the plurality of pixels further includes
a second holding unit that is provided between the first photoelectric conversion unit and the first holding unit and holds charges transferred from the first photoelectric conversion unit, and
a third holding unit that is provided between the second photoelectric conversion unit and the first holding unit and holds charges transferred from the second photoelectric conversion unit, and
transfer of the charges from the first photoelectric conversion unit to the second holding unit and transfer of the charges from the second photoelectric conversion unit to the third holding unit are performed simultaneously in the plurality of pixels.
5. The imaging device according to claim 1 , wherein
in a frame in which the first and second signals are output first among the first and second signals and the third and fourth signals, the third signal is not output, and only the fourth signal is output.
6. The imaging device according to claim 1 , wherein
in a frame in which the third and fourth signals are output first among the first and second signals and the third and fourth signals, the first signal is not output, and only the second signal is output.
7. The imaging device according to claim 1 , wherein
whether to output the first and second signals first or to output the third and fourth signals first in a certain frame is determined based on a signal in a previous frame.
8. The imaging device according to claim 1 , wherein
among the first and second signals and the third and fourth signals, signals output first in each frame are used for focus detection, and
the second signal and the third signal are used for high dynamic range imaging.
9. The imaging device according to claim 1 , wherein
the plurality of pixels are arranged in a plurality of rows,
the plurality of rows includes
a plurality of first rows each including the pixels that output the first signal, the second signal, the third signal, and the fourth signal, and
a plurality of second rows each including the pixels that output only the second signal and the fourth signal, and
readout from the pixels in the plurality of first rows are performed before readout from the pixels in the plurality of second rows.
10. The imaging device according to claim 1 , further comprising:
a control signal supplying unit that supplies, to the plurality of pixels, control signals for outputting the first signal, the second signal, the third signal, and the fourth signal.
11. An imaging system comprising:
an imaging device according to claim 1 ; and
a signal processing unit that processes signals output from the imaging device.
12. An imaging device comprising:
a plurality of pixels each including a first photoelectric conversion unit on which a first part of pupil-divided incident light is incident; a second photoelectric conversion unit on which a second part of the pupil-divided incident light is incident; a first holding unit and a second holding unit that hold charges transferred from the first photoelectric conversion unit; a third holding unit and a fourth holding unit that hold charges transferred from the second photoelectric conversion unit; a fifth holding unit that holds charges transferred from the first holding unit and the third holding unit; a sixth holding unit that holds charges transferred from the second holding unit and the fourth holding unit; a first amplifier unit that outputs a signal based on an amount of the charges held by the fifth holding unit; and a second amplifier unit that outputs a signal based on an amount of the charges held by the sixth holding unit, wherein
the first holding unit is configured to hold charges generated by the first photoelectric conversion unit during a first exposure period, the second holding unit is configured to hold charges generated by the first photoelectric conversion unit during a second exposure period, which is shorter than the first exposure period, the third holding unit is configured to hold charges generated by the second photoelectric conversion unit during the first exposure period, and the fourth holding unit is configured to hold charges generated by the second photoelectric conversion unit during the second exposure period, and
each of the plurality of pixels is configured to output a first signal based on an amount of the charges generated by the first photoelectric conversion unit during the first exposure period, a second signal based on an amount of the charges generated by the first photoelectric conversion unit and the second photoelectric conversion unit during the first exposure period, a third signal based on an amount of the charges generated by the first photoelectric conversion unit during the second exposure period, and a fourth signal based on an amount of the charges generated by the first photoelectric conversion unit and the second photoelectric conversion unit during the second exposure period.
13. The imaging device according to claim 12 , wherein
the first and third signals are output simultaneously, and the second and fourth signals are output simultaneously.
14. The imaging device according to claim 12 , wherein
each of the plurality of pixels further includes
a first charge draining transistor connected to the first photoelectric conversion unit; and
a second charge draining transistor connected to the second photoelectric conversion unit.
15. The imaging device according to claim 12 , wherein
a temporal center of the first exposure period and a temporal center of the second exposure period coincide with each other.
16. The imaging device according to claim 12 , wherein
among the first and second signals and the third and fourth signals, signals output first in each frame are used for focus detection, and
the second signal and the third signal are used for high dynamic range imaging.
17. The imaging device according to claim 12 , wherein
the plurality of pixels are arranged in a plurality of rows,
the plurality of rows includes
a plurality of first rows each including the pixels that output the first signal, the second signal, the third signal, and the fourth signal, and
a plurality of second rows each including the pixels that output only the second signal and the fourth signal, and
readout from the pixels in the plurality of first rows are performed before readout from the pixels in the plurality of second rows.
18. The imaging device according to claim 12 , further comprising:
a control signal supplying unit that supplies, to the plurality of pixels, control signals for outputting the first signal, the second signal, the third signal, and the fourth signal.
19. An imaging system comprising:
an imaging device according to claim 12 ; and
a signal processing unit that processes signals output from the imaging device.
20. A method for driving an imaging device including a plurality of pixels each including a first photoelectric conversion unit on which a first part of pupil-divided incident light is incident, a second photoelectric conversion unit on which a second part of the pupil-divided incident light is incident, a first holding unit that holds charges transferred from the first photoelectric conversion unit and the second photoelectric conversion unit, and an amplifier unit that outputs a signal based on an amount of the charges held by the first holding unit, the method comprising:
outputting a first signal based on an amount of charges generated by the first photoelectric conversion unit during a first exposure time;
outputting a second signal based on an amount of charges generated by the first photoelectric conversion unit and the second photoelectric conversion unit during the first exposure time;
outputting a third signal based on an amount of charges generated by the first photoelectric conversion unit during a second exposure time, which is shorter than the first exposure time; and
outputting a fourth signal based on an amount of charges generated by the first photoelectric conversion unit and the second photoelectric conversion unit during the second exposure time, wherein
the first and second signals are output before the third and fourth signals in a certain one of frames, and output after the third and fourth signals in another one of the frames.