Image capturing apparatus, control method for the same, and storage medium
AssigneeCanon Kabushiki Kaisha
InventorTakenori Kobuse
Life of this patent
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Abstract
An image capturing apparatus including a pixel portion in which pixels that convert entered light into electric signals are arranged in a matrix, a column output line provided for each pixel column of the pixel portion, a clip portion configured to clip, at a predetermined signal level, signals respectively output from the pixels to the column output lines, an A/D conversion portion configured to A/D convert the signals clipped by the clip portion, and a control unit configured to change a signal level at which clipping is performed by the clip portion according to a maximum value of a conversion range of the A/D conversion portion.
Claims9
An image capturing apparatus comprising:
- a pixel portion in which pixels that convert entered light into electric signals are arranged in a matrix;
- a column output line provided for each pixel column of the pixel portion;
- a clip circuit configured to clip, at a predetermined signal level, signals respectively output from the pixels to the column output lines;
- an A/D converter configured to A/D convert the signals clipped by the clip circuit;
- a controller circuit configured to change a signal level at which clipping is performed by the clip circuit, according to a maximum value of a conversion range of the A/D converter;
- and a correction circuit configured to correct streak-shaped or band-shaped noise of the A/D converted signals in a line direction caused by high luminance light that enters the pixel portion, wherein the clip circuit is arranged at a preceding stage of a comparison circuit of the A/D converter and clips analog signals respectively output from the pixels to the column output lines, and
- wherein the analog signals are clipped to a value that is smaller than a maximum value of a ramp signal input to the comparison circuit and a digital gain is applied to the A/D converted signals to compensate a difference between the clipped value and the maximum value of the ramp signal.
A method for controlling an image capturing apparatus that includes a pixel portion in which pixels that convert entered light into electric signals are arranged in a matrix and a column output line provided for each pixel column of the pixel portion, the method comprising:
- clipping, at a predetermined signal level, signals respectively output from the pixels to the column output lines;
- A/D converting the signals clipped in the clipping;
- changing a signal level at which clipping is performed in the clipping according to a maximum value of a conversion range in the A/D conversion;
- and
- correcting streak-shaped or band-shaped noise of the A/D converted signals in a line direction caused by high luminance light that enters the pixel portion,
- wherein the clipping is executed at a preceding stage of a comparison circuit of the A/D converter to clip analog signals respectively output from the pixels to the column output lines, and
- wherein the analog signals are clipped to a value that is smaller than a maximum value of a ramp signal input to the comparison circuit and a digital gain is applied to the A/D converted signals to compensate a difference between the clipped value and the maximum value of the ramp signal.
A non-transitory computer-readable storage medium storing a program for causing a computer to execute each step of a control method for an image capturing apparatus that includes a pixel portion in which pixels that convert entered light into electric signals are arranged in a matrix and a column output line provided for each pixel column of the pixel portion, the control method comprising:
- clipping, at a predetermined signal level, signals respectively output from the pixels to the column output lines;
- A/D converting the signals clipped in the clipping;
- changing a signal level at which clipping is performed in the clipping according to a maximum value of a conversion range in the A/D conversion;
- and
- correcting streak-shaped or band-shaped noise of the A/D converted signals in a line direction caused by high luminance light that enters the pixel portion,
- wherein the clipping is executed at a preceding stage of a comparison circuit of the A/D converter to clip analog signals respectively output from the pixels to the column output lines, and
- wherein the analog signals are clipped to value that is smaller than a maximum value of a ramp signal input to the comparison circuit and a digital gain is applied to the A/D converted signals to compensate a difference between the clipped value and the maximum value of the ramp signal.
Dependencies are inferred from the claim text.