Image pixel and image pixel control method
AssigneeSK hynix Inc.
InventorWoong Hee Lee
Life of this patent
Estimating the term…
Abstract
An image pixel control method includes: performing an initialization process comprising initializing the light receiving unit; performing an excess value sampling process comprising sampling a voltage level corresponding to a quantity of photoelectrons in excess of a photoelectron accommodation capacity of the light receiving unit; performing an initialization level comprising sampling process sampling a voltage level applied to the light receiving unit when the light receiving unit is initialized; and performing a data level sampling process comprising sampling a voltage level corresponding to a quantity of photoelectrons accommodated in the light receiving unit.
Claims15
A method of controlling an image pixel including a light receiving unit configured to generate photocharges through receiving light and accommodate the generated photocharges, a buffer unit configured to accommodate the photocharges, a first transistor configured to electrically connect the light receiving unit and the buffer unit and a second transistor configured to electrically connect the buffer unit and a power source supplying an initialization voltage, comprising:
- performing an initialization process comprising initializing the light receiving unit by applying the initialization voltage to the light receiving unit;
- performing an excess value sampling process comprising sampling a voltage level corresponding to a quantity of photoelectrons in excess of a photoelectron accommodation capacity of the light receiving unit;
- performing an initialization level sampling process comprising applying the initialization voltage to the buffer unit and sampling the initialization voltage of the buffer unit and
- performing a data level sampling process comprising distributing the photoelectrons accommodated in the light receiving unit to the buffer unit and sampling the voltage level of the buffer unit,
- wherein in the excess value sampling process, the second transistor is turned off, a gate voltage of the first transistor is maintained at a pre-set level to transfer the photoelectrons in excess of a photoelectron accommodation capacity of the light receiving unit to the buffer unit, and a voltage level of the buffer unit is sampled,
- wherein the pre-set level of the gate voltage of the first transistor in the excess value sampling process is equal to or higher than a threshold voltage of the first transistor, and
- wherein in the data level sampling process, the second transistor is turned off, and the first transistor is turned on to allow the photoelectrons of the light receiving unit to be shared by the buffer unit, and the voltage level of the buffer unit is sampled.
An image pixel comprising:
- a light receiving unit configured to generate photocharges by receiving light, and accommodate the generated photocharges;
- a buffer unit configured to accommodate charges;
- a first transistor configured to electrically connect the light receiving unit and the buffer unit;
- a second transistor configured to electrically connect the buffer unit and a power source;
- a third transistor configured to electrically connect the buffer unit and an external device;
- and
- a controller configured to control an ON/OFF operation of the respective transistors by adjusting a voltage level applied to the gates of the first, second, and third transistors,
- wherein the controller turns the second transistor and the first transistor on to initialize the light receiving unit, applies a pre-set voltage level to the gate of the first transistor to transfer photoelectrons in excess of a photoelectron accommodation capacity of the light receiving unit to the buffer unit, turns the third transistor on to output voltage level information of the buffer unit to an external device, turns the second transistor and the third transistor on to output the voltage level information of the buffer unit to the external device, turns the first transistor on to allow the photoelectrons accommodated in the light receiving unit to be shared by the buffer unit, and turns the third transistor on to output the voltage level information of the buffer unit to the external device, and
- wherein the pre-set voltage level applied to the gate of the first transistor is equal to or higher than a threshold voltage level of the first transistor.
Dependencies are inferred from the claim text.