Solid state image pickup device, method of driving solid state image pickup device, and camera using the solid state image pickup device

• US 20050121519A1
• Filed: 11/19/2004
• Published: 06/09/2005
• Est. Priority Date: 12/05/2003
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Shinohara, Mahito
• Granted Patent: US 7,394,492 B2
• Time in Patent Office: Days
• US Class Current: 235/454
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H04N 25/59 by controlling the amount of charge storable in the pixel, e.g. modification of the charge conversion ratio of the floating node capacitance
• CPC Class Codes: H04N 25/65 applied to reset noise, e.g. KTC noise related to CMOS structures by techniques other than CDS
• CPC Class Codes: H04N 25/77 Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components
• CPC Class Codes: H04N 3/155 Control of the image-sensor operation, e.g. image processing within the image-sensor

Abstract

Provided is an amplification type solid state image pickup device capable of increasing a saturation charge amount even when an increase in circuit scale is suppressed. In a pixel of the amplification type solid state image pickup device, a power source voltage is supplied to a signal output line to change a potential of the signal output line at transfer operation that a signal charge accumulated in a photo diode is transferred to a gate of an amplification transistor. Then, a potential of an FD portion which is capacitively coupled to the signal output line and used for supplying the signal charge to the gate of the amplification transistor increases, so that the saturation charge amount can be set to a large value.

Claims

1. A solid state image pickup device, comprising an arrangement of a plurality of unit pixels, each of which includes a photo diode for accumulating a signal charge generated by incident light, an amplification transistor whose control electrode receives the signal charge from the photo diode and which outputs an amplification signal corresponding to the signal charge to a signal output line, a reset transistor for resetting the control electrode of the amplification transistor, and a transfer transistor for transferring the signal charge accumulated in the photo diode to the control electrode of the amplification transistor, wherein

a predetermined potential is supplied to the signal output line at transfer operation for transferring the signal charge accumulated in the photo diode to the control electrode of the amplification transistor.

2. A solid state image pickup device according to claim 1, wherein the predetermined potential comprises a potential having a potential difference with respect to a reset potential in a direction reverse to a direction in which a potential of the control electrode of the amplification transistor is changed from the reset voltage when the amplification signal is outputted.

3. A solid state image pickup device according to claim 1, wherein a voltage which is to be supplied to a power source supply terminal of the amplification transistor at the reset operation for resetting the control electrode of the amplification transistor is different from a potential which is to be supplied to the power source supply terminal of the amplification transistor at the transfer operation.

4. A solid state image pickup device according to claim 3, wherein the potential supplied to the power source supply terminal at the transfer operation comprises a potential having a potential difference with respect to the potential supplied to the power source supply terminal at the reset operation in a direction reverse to a direction in which a potential of the control electrode of the amplification transistor is changed from a reset voltage when the amplification signal is outputted.

13. A camera, comprising:

the solid state image pickup device according to claim 1 or 5;

a lens for forming an optical image in the solid state image pickup device; and

a diaphragm capable of changing an amount of light passing through the lens.

5. A solid state image pickup device, comprising an arrangement of a plurality of unit pixels, each of which includes a photo diode for accumulating a signal charge generated by incident light, an amplification transistor whose control electrode receives the signal charge from the photo diode and which outputs an amplification signal corresponding to the signal charge to a signal output line, a reset transistor for resetting the control electrode of the amplification transistor, and a transfer transistor for transferring the signal charge accumulated in the photo diode to the control electrode of the amplification transistor, wherein

a voltage which is to be supplied to a power source supply terminal of the amplification transistor at the reset operation for resetting the control electrode of the amplification transistor is different from a potential which is to be supplied to the power source supply terminal of the amplification transistor at the transfer operation for transferring the signal charge accumulated in the photo diode to the control electrode of the amplification transistor.

6. A solid state image pickup device according to claim 5, wherein the potential supplied to the power source supply terminal at the transfer operation comprises a potential having a potential difference with respect to a potential supplied to the power supply terminal at the reset operation in a direction reverse to a direction in which a potential of the control electrode of the amplification transistor is changed from a reset voltage when the amplification signal is outputted.

7. A solid state image pickup device, comprising an arrangement of a plurality of unit pixels, each of which includes a photo diode for accumulating a signal charge generated by incident light, an amplification transistor whose control electrode receives the signal charge from the photo diode and which outputs an amplification signal corresponding to the signal charge to a signal output line, a reset transistor for resetting the control electrode of the amplification transistor, and a transfer transistor for transferring the signal charge accumulated in the photo diode to the control electrode of the amplification transistor, wherein

a predetermined potential is supplied to the signal output line when the transfer transistor is in an on-state.

8. A solid state image pickup device according to claim 7, wherein a potential supplied to a power source supply terminal of the amplification transistor when the reset transistor is in an on-state is different from a potential supplied to the power source supply terminal of the amplification transistor when the transfer transistor is in the on-state.

9. A solid state image pickup device, comprising:

an arrangement of a plurality of unit pixels, each of which includes

a photo diode for accumulating a signal charge generated by incident light,

a first transistor,

a second transistor whose gate is connected with a cathode of the photo diode through the first transistor, whose drain is connected with a power source wiring for supplying a power source voltage, and whose source is connected with a signal output line for outputting an amplification signal,

a third transistor whose drain is connected with the power source wiring and whose source is connected with the gate of the second transistor, and

a first capacitor whose first electrode is connected with the gate of the second transistor and whose second electrode is connected with the signal output line; and

a fourth transistor whose drain is connected with the signal output line and whose source is connected with a power source terminal.

10. A solid state image pickup device according to claim 9, wherein each of the unit pixels further includes a second capacitor whose first electrode is connected with the power source wiring and whose second electrode is connected with the gate of the second transistor,

wherein the solid state image pickup device further comprises

a fifth transistor whose drain is connected with the power source wiring and whose source is connected with a first power source terminal, and

a sixth transistor whose drain is connected with a second power source terminal for supplying a potential different from a potential supplied from the first power source terminal and whose source is connected with the power source wiring,

wherein the gate of the fifth transistor and the gate of the sixth transistor are commonly connected with a control line.

11. A method of driving a solid state image pickup device comprising an arrangement of a plurality of unit pixels, each of which includes a photo diode for accumulating a signal charge generated by incident light, an amplification transistor whose control electrode receives the signal charge from the photo diode and which outputs an amplification signal corresponding to the signal charge to a signal output line, a reset transistor for resetting the control electrode of the amplification transistor, and a transfer transistor for transferring the signal charge accumulated in the photo diode to the control electrode of the amplification transistor, the method comprising:

setting a potential of the signal output line at a predetermined potential at transfer operation for transferring the signal charge accumulated in the photo diode to the control electrode of the amplification transistor.

12. A method of driving a solid state image pickup device comprising an arrangement of a plurality of unit pixels, each of which includes a photo diode for accumulating a signal charge generated by incident light, an amplification transistor whose control electrode receives the signal charge from the photo diode and which outputs an amplification signal corresponding to the signal charge to a signal output line, a reset transistor for resetting the control electrode of the amplification transistor, and a transfer transistor for transferring the signal charge accumulated in the photo diode to the control electrode of the amplification transistor, the method comprising:

setting a first potential to be supplied to a power source supply terminal of the amplification transistor at reset operation for resetting the control electrode of the amplification transistor; and

setting a second potential different from the first potential, which is to be supplied to the power source supply terminal of the amplification transistor at transfer operation for transferring the signal charge accumulated in the photo diode to the control electrode of the amplification transistor.