Image sensor
An image sensor including: a plurality of first photoelectric conversion elements included in a first region of a pixel; a plurality of second photoelectric conversion elements included in a second region of the pixel; a first overflow capacitor connected to the plurality of first photoelectric conversion elements to store overflow charges of the first photoelectric conversion elements; a second overflow capacitor connected to the plurality of second photoelectric conversion elements to store overflow charges of the second photoelectric conversion elements; and one or more microlenses disposed on the pixel.
1 . An image sensor comprising:
a plurality of first photoelectric conversion elements included in a first region of a unit pixel;
a plurality of second photoelectric conversion elements included in a second region of the unit pixel;
a first overflow capacitor connected to the plurality of first photoelectric conversion elements to store overflow charges of the first photoelectric conversion elements;
a second overflow capacitor connected to the plurality of second photoelectric conversion elements to store overflow charges of the second photoelectric conversion elements; and
two or more microlenses disposed on the unit pixel,
wherein the first region and the second region respectively correspond to a first side of two or more microlenses and a second side of two or more microlenses.
2 . The image sensor of claim 1 , wherein the first region corresponds to a left side of the two or more microlenses,
wherein the second region corresponds to a right side of the two or more microlenses.
3 . The image sensor of claim 1 , further comprising:
a plurality of first overflow gate transistors respectively connected to the plurality of first photoelectric conversion elements; and
a plurality of second overflow gate transistors respectively connected to the plurality of second photoelectric conversion elements.
4 . The image sensor of claim 3 , wherein the plurality of first overflow gate transistors are respectively connected between the plurality of first photoelectric conversion elements and the first overflow capacitor,
wherein the plurality of second overflow gate transistors are respectively connected between the plurality of second photoelectric conversion elements and the second overflow capacitor.
5 . The image sensor of claim 1 , wherein the first overflow capacitor and the second overflow capacitor comprise dynamic random access memory (DRAM) capacitors.
6 . An image sensor comprising a pixel array in which a plurality of pixels are arranged,
wherein the pixel array comprises:
unit pixels each including a plurality of sub-pixels; and
one or more auto focusing (AF) pixels including a first sub-pixel group and a second sub-pixel group of the plurality of sub-pixels,
wherein one microlens is disposed above each of the one or more AF pixels,
wherein first photodiodes corresponding to the first sub-pixel group included in the one or more AF pixels are electrically connected to a transfer circuit included in the one or more AF pixels,
wherein the transfer circuit comprises an overflow capacitor for storing overflow charges of the photodiodes corresponding to the first sub-pixel group, and
wherein a first region and a second region respectively correspond to a first side of the microlens and a second side of the microlens.
7 . The image sensor of claim 6 , wherein photodiodes corresponding to the second sub-pixel group included in the AF pixel are not electrically connected to a transfer circuit included in the AF pixel.
8 . The image sensor of claim 7 , further comprising a blocking member disposed between the second sub-pixel and the microlens.
9 . The image sensor of claim 8 , wherein the blocking member includes a light blocking material.
10 . The image sensor of claim 7 , wherein the photodiodes corresponding to the second sub-pixel group are connected to a pixel voltage and a ground voltage.
11 . The image sensor of claim 7 , wherein the photodiodes corresponding to the second sub-pixel group each comprise a plurality of transfer transistors connected thereto,
wherein gates of the plurality of transfer transistors are connected to a ground voltage.
12 . The image sensor of claim 11 , wherein the photodiodes corresponding to the second sub-pixel group are connected to a pixel voltage and a ground voltage.
13 . The image sensor of claim 7 , wherein the first sub-pixel group is disposed on a left side of the microlens or a right side of the microlens,
wherein the second sub-pixel group does not overlap the first sub-pixel group.
14 . The image sensor of claim 6 , wherein the number of sub-pixels overlapped by the microlens is 8.
15 . The image sensor of claim 6 , wherein the overflow capacitor comprises a dynamic random access memory (DRAM) capacitor.
16 . An image sensor comprising a pixel array including one or more auto focusing (AF) pixels,
wherein a microlens is disposed on the AF pixel,
wherein the AF pixel comprises:
a plurality of photodiodes corresponding to a plurality of sub-pixels included in the AF pixel;
a plurality of transfer transistors configured to transfer photocharges of the plurality of photodiodes to a transfer circuit; and
the transfer circuit including a plurality of overflow capacitors for storing overflow charges of the plurality of photodiodes,
wherein first overflow charges of a photodiode included in a region corresponding to a first region of the microlens are stored in a first overflow capacitor of the plurality of overflow capacitors,
wherein second overflow charges of a photodiode included in a region corresponding to a second region of the microlens stored in a second overflow capacitor of the plurality of overflow capacitors, and
wherein the first overflow charges and the second overflow charges are processed independently of each other.
17 . The image sensor of claim 16 , wherein the transfer circuit comprises:
a first overflow gate transistor for controlling the overflow charges of the photodiode included in the region corresponding to the first region of the microlens; and
a second overflow gate transistor for controlling the overflow charges of the photodiode included in the region corresponding to the second region of the microlens.
18 . The image sensor of claim 16 , wherein the photodiode included in the region corresponding to the first region of the microlens is electrically connected to the transfer circuit,
wherein the photodiode included in the region corresponding to the second region of the microlens is electrically separated from the transfer circuit.
19 . The image sensor of claim 18 , wherein photoelectric charges and overflow charges of the photodiode included in the region corresponding to the second region of the microlens are drained as a pixel voltage of the AF pixel.
20 . The image sensor of claim 16 , wherein the overflow capacitor comprises a dynamic random access memory (DRAM) capacitor.