Solid state image pickup device having a time pulse generator, and method for replacing signals from a switch

A method for driving the read-out of a solid state image pickup device provided with a plurality of photoelectric converter portions arranged in a plurality of rows, each row composed of a plurality of pixels, and a plurality of charge transfer portions for transferring the charges generated in respective rows of pixels, wherein,

• a switch circuit selects between two modes, comprising:
• a first mode in which the switch circuit passes drive pulses are generated by a pulse generator to the charge transfer portions, and
• a second mode in which the switch circuit replaces at least one of the drive pulses with a floating level, and wherein
• a different driving pulse is subsequently applied to the same input at which the driving pulse is replaced with the floating level.

A solid state image pickup device being provided with a plurality of photoelectric converter portions arranged in a plurality of rows, each row having a plurality of pixels, a plurality of charge transfer portions for transferring the charges generated in said photoelectric converter portions, and a plurality of charge/voltage converter portions for converting the charges transferred by each charge transfer portion into voltages, further comprising:

• a first switch circuit operable to selectively connect a first input of at least one of the transfer registers to one of a group of signals comprised of:
• a first pulse signal, a fixed voltage level, and a float level;
• and
• a second switch circuit operable to selectively connect a second input of at least one of the transfer registers to one of a group of signals comprised of:
• a second pulse signal, a fixed voltage level, and a float level, wherein the transfer register receives a float level when not in use.