Solid-state image sensor

A solid-state image sensor comprising:

• a) a pixel area in which a plurality of pixels are arranged, each pixel including photoelectric conversion element for receiving light and generating photocharges, a transfer element for transferring the photocharges generated by the photoelectric conversion element to a detection node for converting a charge signal into a voltage signal and a buffer element for sending an output signal from the detection node to a below-mentioned pixel output line;
• b) a memory area, which is separated from the pixel area and includes as many memory units as the pixels, one memory unit being provided for each pixel and each memory unit including a plurality of memory sections, in order to hold signals produced by each pixel over a plurality of frames;
• and
• c) pixel output lines connecting the pixel area and the memory area, the number of the pixel output lines is obtained when the total number of pixels included in the pixel area is divided by n where n is an integer equal to or greater than two, and n pixels in the pixel area and n memory units in the memory area are connected to each of the pixel output lines, the n memory units being provided for the n pixels in order to hold signals produced by the n pixels over a plurality of frames;
• wherein a writing-side gate element and a reading-side gate element are provided on each of the pixel output lines, the writing-side gate element being located between the n pixels and the n memory units, and the reading-side gate element being located on the opposite side of the writing-side gate element with respect to the plurality of the memory sections.

A solid-state image sensor,

• comprising:
• a) a pixel area in which a plurality of pixels are arranged, each pixel including photoelectric conversion element for receiving light and generating photocharges, a transfer element for transferring the photocharges generated by the photoelectric conversion element to a detection node for converting a charge signal into a voltage signal and a buffer element for sending an output signal from the detection node to a below-mentioned pixel output line;
• b) a memory area, which is separated from the pixel area and includes as many memory units as the pixels, one memory unit being provided for each pixel and each memory unit including a plurality of memory sections, in order to hold signals produced by each pixel over a plurality of frames;
• and
• c) pixel output lines connecting the pixel area and the memory area, the number of the pixel output lines is obtained when the total number of pixels included in the pixel area is divided by n where n is an integer equal to or greater than two, and n pixels in the pixel area and n memory units in the memory area are connected to each of the pixel output lines, the n memory units being provided for the n pixels in order to hold signals produced by the n pixels over a plurality of frames;
• wherein the memory sections each include one capacitor and one switch element, and a writing-side gate element and a reading-side gate element are provided on each of the pixel output lines, the writing-side gate element being located between the n pixels and the n memory units, and the reading-side gate element being located on the opposite side of the writing-side gate element with respect to the plurality of the memory sections.