One problem addressed by the present invention is to provide an optical sensor, a solid-state imaging device, and methods for reading the signals therefrom, which contribute greatly to the development of industry and the realization of a safer and more secure society. One solution according to the present invention is an optical sensor having a light-receiving element, storage capacitors that store a charge, and a transfer switch for transferring to the storage capacitors a charge generated by light input to the light-receiving element, wherein the storage capacitors are a floating diffusion capacitor and a lateral overflow integration capacitor, and the transfer switch is a non-LDD/MOS transistor, that is, a non-LDD/MOS transistor for which the impurity concentration of the drain region is reduced by 50%.