In electronics, slew rate is defined as the change of voltage or current, or any other electrical quantity, per unit of time. Expressed in SI units, the unit of measurement is volts/second or amperes/second or the unit being discussed, (but is usually expressed in V/μs). Electronic circuits may specify minimum or maximum limits on the slew rates for their inputs or outputs, with these limits only valid under some set of given conditions (e.g. output loading).
A solid-state imaging device includes: pixel signal reading lines; a pixel unit in which pixels including photoelectric conversion elements are arranged; and a pixel signal reading unit performing reading of pixel signals from the pixel unit through the pixel signal reading lines, wherein the pixel signal reading unit includes current source circuits each of which includes a load element as a current source connected to the pixel signal reading line forming a source follower, and the current source circuit includes a circuit generating electric current according to a slew rate of the pixel signal reading line and replicating electric current corresponding to the above electric current to flow in the current source.