IMAGE SENSOR FOR REMOVING HORIZONTAL NOISE
Disclosed herein is an image sensor for removing a horizontal noise. The image sensor includes a pixel array including a plurality of unit pixels located at every row or column; an analog bus located at every row or column, for transferring output signals of the pixel array; and a readout circuit for reading the output signals of the pixel array loaded on the analog bus, wherein the readout circuit includes: a plurality of first transistors having a drain connected to the column analog bus and a source connected to a supply voltage; and a second transistor having a drain connected to a gate of the second transistor and gates of the first transistors, and a source connected to the supply voltage, wherein, a size of the second transistor is larger than a size of the first transistor.
1 . An image sensor, comprising:
a pixel array including a plurality of unit pixels located at every row or column;
an analog bus located at every row or column, for transferring output signals of the pixel array; and
a readout circuit for reading the output signals of the pixel array loaded on the analog bus,
wherein the readout circuit includes:
a plurality of first transistors having a drain connected to the column analog bus and a source connected to a supply voltage; and
a second transistor having a drain connected to a gate of the second transistor and gates of the first transistors, and a source connected to the supply voltage,
wherein, a size of the second transistor is larger than a size of the first transistor.
2 . The image sensor as recited in claim 1 , wherein an amount of current flowing via the second transistor is relatively larger than a current amount flowing on the first transistor.
3 . The image sensor as recited in claim 2 , wherein the first transistors are located at every row and the second transistor forms current mirrors with the first transistors.
4 . The image sensor as recited in claim 2 , wherein the first transistors are located at every column and the second transistor forms current mirrors with the first transistors.
5 . The image sensor as recited in claim 2 , wherein the first transistors and the second transistor are NMOS transistor.
6 . The image sensor as recited in claim 2 , wherein the supply voltage is a ground voltage.
7 . An image sensor, comprising:
a pixel array including a plurality of unit pixels located at every row or column;
an analog bus located at every row or column for transferring output signals of the pixel array; and
a readout circuit for reading the output signals of the pixel array loaded on the analog bus,
wherein the readout circuit includes:
a plurality of first transistors having a drain connected to the column analog bus and a source connected to a supply voltage; and
a second transistor having a drain connected to a gate of the second transistor and gates of the first transistors, and a source connected to the supply voltage,
wherein an amount of the second current is larger than an amount of the first current.
8 . The image sensor as recited in claim 7 , wherein the first transistors are located at every row and the second transistor forms current mirrors with the first transistors.
9 . The image sensor as recited in claim 7 , wherein the first transistors are located at every column and the second transistor forms current mirrors with the first transistors.
10 . The image sensor as recited in claim 7 , wherein the first transistors and the second transistor are NMOS transistor.
11 . The image sensor as recited in claim 7 , wherein the supply voltage is a ground voltage.