1. In a reading device of the type having a plurality of scanning type image sensors for covering a plurality of regions of an image to be read, said image sensors being disposed adjacent one another in a scanning direction and, in response to respective scanning signals, sequentially providing respective image sensor output signals which are combined into a synthetic video signal representing the read image, a control circuit comprising: means for providing scanning signals to said plurality of image sensors during individual time intervals which collectively span a continuous time interval; start position control means for determining a start time at which the output signal of a first of said plurality of sensors is to be provided as a part of said synthetic video signal; set position control means for determining, in accordance with said first start time, remaining start times at which outputs from the remainder of said plurality of sensors are provided as part of said synthetic video signal; and signal selection means for selecting outputs from said image sensors in accordance with the times determined by said start position and set position control means.