SOLID-STATE IMAGING APPARATUS, DRIVING METHOD THEREOF AND IMAGING SYSTEM

• US 20090303365A1
• Filed: 06/02/2009
• Published: 12/10/2009
• Est. Priority Date: 06/06/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Watanabe, Takanori
• Granted Patent: US 8,730,345 B2
• Time in Patent Office: Days
• US Class Current: 348/302
• CPC Class Codes: H01L 27/14641 Electronic components shared by two or more pixel-elements, e.g. one amplifier shared by two pixel elements
• CPC Class Codes: H04N 23/745 Detection of flicker frequency or suppression of flicker wherein the flicker is caused by illumination, e.g. due to fluorescent tube illumination or pulsed LED illumination
• CPC Class Codes: H04N 25/53 Control of the integration time
• CPC Class Codes: H04N 25/531 by controlling rolling shutters in CMOS SSIS
• CPC Class Codes: H04N 25/778 comprising amplifiers shared between a plurality of pixels, i.e. at least one part of the amplifier must be on the sensor array itself

Abstract

A solid-state imaging apparatus includes: a plurality of photoelectric conversion elements arranged in a matrix and converting light into electric carriers; a transfer gate for transferring the electric carriers generated by the conversion to a floating node; a first transistor for amplifying a signal based on a voltage of the floating node and for outputting the amplified signal to a column signal line; and a second transistor for resetting the voltage of the floating node, wherein the solid-state imaging apparatus includes a transfer unit for combining signals from the column signal lines, based on the voltage of the floating nodes after the reset of the floating nodes by the second transistor, wherein outputting a signal based on the combined signals from the column signal lines based on the voltage of the floating nodes, for detecting a flicker of an imaging light source.

Claims

1. A solid-state imaging apparatus comprising:

a plurality of photoelectric conversion elements arranged in a matrix and converting light into electric carriers;

a transfer gate for transferring the electric carriers generated by the conversion to a floating node;

a first transistor for amplifying a signal based on a voltage of the floating node and for outputting the amplified signal to a column signal line; and

a second transistor for resetting the voltage of the floating node, wherein

the solid-state imaging apparatus comprises a transfer unit for combining signals from the column signal lines, based on the voltage of the floating nodes after the reset of the floating nodes by the second transistor, and for outputting a signal based on the combined signals from the column signal lines based on the voltage of the floating nodes, to detect a flicker of an imaging light source.

2. The solid-state imaging apparatus according to claim 1, wherein

the transfer unit outputs, as an pixel signal, column by column, a difference signal between a signal of the column signal line based on the electric carriers of the floating node transferred by the transfer gate and a signal of the column signal line based on a signal of the floating node after the reset by the second transistor.

3. The solid-state imaging apparatus according to claim 1, wherein

in the floating node, based on the light incident in a semiconductor region from the light source, or based on the electric carrier diffusion within a semiconductor substrate, the signal for detecting the flicker of the imaging light source is generated.

4. The solid-state imaging apparatus according to claim 2, wherein

the transfer unit outputs the pixel signal for all rows of the pixels, and the signal for detecting the flicker of the imaging light source for a part of the rows of the pixels.

5. An imaging system comprising:

a solid-state imaging apparatus according to claim 4;

an AFE block for inputting, from the same path within the solid-state imaging apparatus in a time series, the pixel signal and the signal for detecting the flicker of the imaging light source outputted from the solid-state imaging apparatus, and for outputting to different paths the pixel signal and the signal for detecting the flicker of the imaging light source;

a flicker detection block for outputting a determination value indicating an existence or an inexistence of the flicker of the imaging light source, based on the signal for detecting the flicker of the imaging light source outputted from the AFE block; and

a timing generator for outputting a drive pulse of a flicker reducing drive mode or a normal drive mode according to the determination value.

6. A solid-state imaging apparatus comprising:

a plurality of photoelectric conversion elements arranged in a matrix and converting light into electric carriers;

a transfer gate for transferring the electric carriers generated by the conversion to a floating node;

a first transistor for amplifying a signal based on a voltage of the floating node and for outputting the amplified signal to a column signal line; and

a second transistor for resetting the voltage of the floating node, wherein

the solid-state imaging apparatus comprises a transfer unit for combining signals from the column signal lines based on the voltage of the floating nodes after the reset of the floating nodes by the second transistor, and for outputting the combined signals from the column signal lines based on the voltage of the floating nodes, during a first reading period for reading the signal based on the electric carriers and the signal after the reset of the voltage of the floating node by the second transistor and during a second reading period different from the first reading period.

7. The solid-state imaging apparatus according to claim 6, wherein

based on the signal read out during the second reading period, the flicker is detected.

8. A driving method of a solid-state imaging apparatus comprising, wherein the solid-state imaging apparatus comprises:

a plurality of photoelectric conversion elements arranged in a matrix and converting light into electric carriers;

a transfer gate for transferring the electric carriers generated by the conversion to a floating node;

a first transistor for amplifying a signal based on a voltage of the floating node and for outputting the amplified signal to a column signal line; and

a second transistor for resetting the voltage of the floating node, wherein

the driving method comprising;

a step of combining signals from the column signal lines based on the voltage of the floating nodes after the reset of the floating nodes by the second transistor, and

a step of detecting a flicker of an imaging light source based on the signal derived by the combining step.