Solid-state imaging device, imaging device, electronic equipment, a/d converter and a/d conversion method

An imaging device comprising:

• a pixel array section having unit pixels arranged in a matrix form, each of the unit pixels having a charge generation section and a transistor that outputs a target signal containing reset and signal levels commensurate with a signal charge generated by the charge generation section;
• a reference signal generation section that generates a reference signal whose level changes gradually;
• an A/D conversion unit, the A/D conversion unit comprising:
• a comparison section that compares each of the reset and signal levels of the target signal against the reference signal output from the reference signal generation section, and
• a counter section that performs a counting based on a count clock and a result of the comparison of each of the reset and signal levels of the target signal against the reference signal, the A/D conversion unit obtaining digital data which is a difference between the reset and signal levels based on the output data of the counter section, and the A/D conversion unit being provided one for each column of the pixel array section, the imaging device further comprising:
• a drive control section that controls the reference signal generation section and A/D conversion unit to perform a digital integration that repeats an n-bit A/D conversion on the reset and signal levels W times, where W is a positive integer equal to or greater than 2;
• and
• a main control section that controls the drive control section,
• wherein,
• the drive control section sets a factor for each of a plurality of target signals and obtains digital data of the plurality of target signals by multiplying each target analog signal by the respective factor and summing the respective results thereof.

Electronic equipment comprising:

• a signal generation section that generates a target analog signal;
• a reference signal generation section that generates a reference signal whose level changes gradually;
• a comparison section that compares the target analog signal and the reference signal;
• a counter section that performs a counting based on a count clock and a result of the comparison of the target analog signal and the reference signal;
• and
• a control section that controls the reference signal generation section, comparison section and counter section to perform a digital integration that repeats an n-bit A/D conversion on the same target analog signal W times, where W is a positive integer equal to or greater than 2,
• wherein,
• the drive control section sets a factor for each of a plurality of target analog signals and obtains digital data of the plurality of target analog signals by multiplying each target analog signal by the respective factor and summing the respective results thereof.

An A/D converter comprising:

• a reference signal generation section that generates a reference signal whose level changes gradually;
• a comparison section that compares an target analog signal and the reference signal;
• a counter section that performs the counting based on a count clock and a result of the comparison of the target analog signal and the reference signal;
• and
• a control section that controls the reference signal generation section, comparison section and counter section to perform a digital integration that repeats an n-bit A/D conversion on the target analog signal W times, where W is a positive integer equal to or greater than 2,
• wherein,
• the drive control section sets a factor for each of a plurality of target analog signals and obtains digital data of the plurality of target analog signals by multiplying each target analog signal by the respective factor and summing the respective results thereof.

An A/D conversion method comprising:

• comparing a reference signal whose level changes gradually and a target analog signal with a comparison section;
• performing a counting based on a count clock and a result of the comparison of the target analog signal and the reference signal;
• and
• repeating an n-bit A/D conversion on the target analog signal W times, where W is a positive integer equal to or greater than 2, to obtain digital data of the target analog signal based on output data of the counter section,
• wherein,
• the drive control section sets a factor for each of a plurality of target analog signals and obtains digital data of the plurality of target analog signals by multiplying each target analog signal by the respective factor and summing the respective results thereof.