a one - dimensional time - delay integration solid - state imager includes a plurality of light - to - electricity conversion parts which store signal charges generated in response to incident light , a vertical ccd corresponding to a series of the light - to - electricity conversion parts for transferring stored signal charges , and a gate for controlling transfer of signal charges stored at the light - to - electricity conversion parts to the vertical ccd . the signal charges corresponding to the same observed image moving on the plurality of light - to - electricity conversion parts are added to enhance the signal - to - noise ratio , and a background signal charge removing region for removing background signal charges is provided at the vertical ccd for removing background charges during the transfer of signal charges .