Image sensor and control method therefor, and image capturing apparatus

An image sensor comprising:

• a pixel unit including pixels each having a plurality of photoelectric conversion portions and corresponding to each of a plurality of microlenses arranged in matrix;
• a generator that generates and outputs a plurality of reference signals whose slopes of potential change per predetermined time are different from each other;
• a selector that selects one of the plurality of reference signals;
• and
• an analog/digital converter that converts an analog signal output from a pixel unit row by row in a first mode or second mode using the reference signal selected by the selector into a digital signal,
• wherein in the first mode, a noise signal output from the pixel unit is converted into a first digital signal using a predetermined one of the plurality of reference signals and a first photoelectric conversion signal obtained by performing photoelectric conversion on incident light and output from the pixel unit is converted into a second digital signal using one of the plurality of reference signals,
• in the second mode, the noise signal is converted into a plurality of first digital signals using the plurality of reference signals and third and fourth photoelectric conversion signals that are read out from the pixel unit so as to be able to obtain a pair of focus detection signals having parallax are converted into third and fourth digital signals, respectively, using one of the plurality of reference signals, and
• signals from a row including an area in which focus detection is performed are processed in the second mode.

An image capturing apparatus comprising:

• an image sensor comprising
• a generator that generates and outputs a plurality of reference signals whose slopes of potential change per predetermined time are different from each other,
• a selector that selects one of the plurality of reference signals, and
• an analog/digital converter that converts an analog signal output from a pixel unit row by row by first driving or second driving using the reference signal selected by the selector into a digital signal;
• and
• a signal processor that processes a signal output from the image sensor,
• wherein in the first driving, a noise signal output from the pixel unit is converted into a plurality of first digital signals using the plurality of reference signals and a photoelectric conversion signal obtained by performing photoelectric conversion on incident light and output from the pixel unit is converted into a second digital signal using one of the plurality of reference signals,
• in the second driving, the noise signal is converted into the first digital signal using a predetermined one of the plurality of reference signals and the photoelectric conversion signal is converted into the second digital signal using one of the plurality of reference signals, and
• the first driving is performed intermittently.

An image capturing apparatus comprising:

• an image sensor comprising
• a pixel unit including pixels each having a plurality of photoelectric conversion portions and corresponding to each of a plurality of microlenses arranged in matrix,
• a generator that generates and outputs a plurality of reference signals whose slopes of potential change per predetermined time are different from each other,
• a selector that selects one of the plurality of reference signals, and
• an analog/digital converter that converts an analog signal output from a pixel unit row by row in a first mode or second mode using the reference signal selected by the selector into a digital signal;
• and
• a signal processor that processes a signal output from the image sensor,
• wherein in the first mode, a noise signal output from the pixel unit is converted into a first digital signal using a predetermined one of the plurality of reference signals and a first photoelectric conversion signal obtained by performing photoelectric conversion on incident light and output from the pixel unit is converted into a second digital signal using one of the plurality of reference signals,
• in the second mode, the noise signal is converted into a plurality of first digital signals using the plurality of reference signals and third and fourth photoelectric conversion signals that are read out from the pixel unit so as to be able to obtain a pair of focus detection signals having parallax are converted into third and fourth digital signals, respectively, using one of the plurality of reference signals, and
• signals from a row including an area in which focus detection is performed are processed in the second mode.

A control method for an image sensor comprising a generator that generates and outputs a plurality of reference signals whose slopes of potential change per predetermined time are different from each other, a selector that selects one of the plurality of reference signals, and an analog/digital converter that converts an analog signal output from a pixel unit row by row by first driving or second driving using the reference signal selected by the selector into a digital signal, the method comprising:

• controlling to perform conversion row by row by the analog/digital converter by the first driving or the second driving;
• converting, in the first driving, a noise signal output from the pixel unit into a plurality of first digital signals using the plurality of reference signals and converting a photoelectric conversion signal obtained by performing photoelectric conversion on incident light and output from the pixel unit into a second digital signal using one of the plurality of reference signals;
• and
• converting, in the second driving, the noise signal into the first digital signal using a predetermined one of the plurality of reference signals and converting the photoelectric conversion signal into the second digital signal using one of the plurality of reference signals,
• wherein the first driving is performed intermittently.

A control method for an image sensor comprising a pixel unit including pixels each having a plurality of photoelectric conversion portions and corresponding to each of a plurality of microlenses arranged in matrix, a generator that generates and outputs a plurality of reference signals whose slopes of potential change per predetermined time are different from each other, a selector that selects one of the plurality of reference signals, and an analog/digital converter that converts an analog signal output from a pixel unit row by row in a first mode or second mode using the reference signal selected by the selector into a digital signal, the method comprising:

• controlling to perform conversion row by row by the analog/digital converter in the first mode or the second mode;
• converting, in the first mode, a noise signal output from the pixel unit into a first digital signal using a predetermined one of the plurality of reference signals and converting a first photoelectric conversion signal obtained by performing photoelectric conversion on incident light and output from the pixel unit into a second digital signal using one of the plurality of reference signals;
• and
• converting, in the second mode, the noise signal is converted into a plurality of first digital signals using the plurality of reference signals and converting third and fourth photoelectric conversion signals that are read out from the pixel unit so as to be able to obtain a pair of focus detection signals having parallax into third and fourth digital signals, respectively, using one of the plurality of reference signals,
• wherein signals from a row including an area in which focus detection is performed are processed in the second mode.