Solid-state image pickup apparatus with high- and low-sensitivity photosensitive cells, and an image shooting method using the same

A method of shooting an image, comprising:

• causing a plurality of photosensitive cells bidimensionally arranged in a photosensitive array on which incident light is condensed to convert the incident light to signal charges;
• separating, by a color filter assigned to the plurality of photosensitive cells, the incident light to red, green and blue, which are three primary colors;
• transferring the signal charges output from the plurality of photosensitive cells at a timing in response to a drive signal;
• providing the plurality of photosensitive cells with at least first photosensitive cells with a first photoelectric conversion sensitivity characteristic and second photosensitive cells with a second photoelectric conversion sensitivity characteristic lower than the first photoelectric conversion sensitivity, the first and second photosensitive cells alternating with each other in a horizontal direction and a vertical direction of a bidimensional arrangement;
• providing the color filter with first portions where red is assigned to the first photosensitive cells, second portions where blue is assigned to the second photosensitive cells, third portions where blue is assigned to the first photosensitive cells and fourth portions where red is assigned to the second photosensitive cells;
• designating, among modes in which the signal charges are read out from the plurality of photosensitive cells, at least one of a progressive read mode for reading out signal charges from all of the plurality of photosensitive cells and a thin-out read mode for reading out signal charges while thinning out the plurality of photosensitive cells;
• and
• generating the drive signal in accordance with the mode designated, and feeding the drive signal to a circuit selected;
• said thin-out read mode comprising a first mode for reading out signal charges from the first portions and said second portions, and a second mode for reading out signal charges from the third portions and the fourth portions, and
• in said designating, one of the first mode and the second mode being designated.

A method of reading out signal charges in a thin-out read mode of a solid-state image pickup apparatus including first photosensitive cells with a first photoelectric conversion sensitivity characteristic and second photosensitive cells with a second photoelectric conversion sensitivity characteristic lower than the first photoelectric conversion sensitivity, and a color filter having red, green and blue colors and which includes first portions where said red color is assigned to said first photosensitive cells, second portions where said blue color is assigned to said second photosensitive cells, third portions where said blue color is assigned to said first photosensitive cells and fourth portions where said red color is assigned to said second photosensitive cells, said method comprising:

• determining a color temperature of a subject to be picked up;
• if it is determined that said color temperature is high, reading out signal charges only from photosensitive cells to which said green color is assigned and photosensitive cells in said first and second portions;
• and
• if it is determined that said color temperature is low, reading out signal charges only from photosensitive cells to which said green color is assigned and photosensitive cells in said third and fourth portions.