In a CMOS image sensor, current leakage after a series of noise removing operations has been completed is suppressed in a read operation for each horizontal line, thereby suppressing image noise occurring on the output display screen of the image sensor. There are provided signal storage regions for storing the signals read from the unit cells in the same row selected in the imaging area onto vertical signal lines and horizontal select transistors for sequentially selecting and reading the signals stored in the individual signal storage regions and transferring them to read horizontal signal lines. At least in the period during which the signals are read from the signal storage regions, one of the drain and source of the transistor electrically connected to the signal path between the vertical signal line and horizontal signal line is biased in the reverse direction with respect to the substrate region. Two adjacent ones of the horizontal select transistors form a pair. The horizontal select transistors in each pair share one of the source/drain regions so as to be connected to the horizontal signal line in common, and the others of the source/drain regions are connected to the vertical signal line individually.
This application is a divisional of and claims benefit under 35 USC 120 from U.S. application Ser. No. 09/322,994, filed Jun. 1, 1999, and is based upon and claims the benefit of priority under 35 USC 119 from Japanese Patent Applications 10-152805, 10-152807, both filed on Jun. 2, 1998 and 11-001139, filed on Jan. 6, 1999; the entire contents of which are incorporated by reference herein.
Priority Data
Jun 02, 1998 [JP] 10-152805 Jun 02, 1998 [JP] 10-152807 Jan 06, 1999 [JP] 11-001139
