Image scanner having system extending function and image correcting function

An image scanner comprising:

• an image read means at least including a lamp, a mirror and CCD sensors to read a manuscript;
• an image control means operatively connected to said image read means to process an image read by said image read means;
• a host computer operatively connected to said image control means;
• and
• said image control means including a main printed-circuit board provided for original functions of said image scanner, a main connector connecting said image control means to said host computer, a user printed-circuit board selectively provided by a user as an extended slot and said board mounted within said image control means, and a user connector connecting said main printed-circuit board to said user printed-circuit board;
• wherein said image control means further comprises;
• a control circuit operatively connected to said CCD sensors;
• a microprocessor connected to said control circuit;
• a driver and a driver/receiver both connected to said control circuit;
• a video connector connected to said driver to send image signals to said host computer;
• a control connector connected to said driver/receiver to send and receive control signals to/from said host computer;
• and an extended connector connected between said control circuit and said extended slot to send and receive the image/control signals to/from said extended slot without passing through said driver and driver/receiver;
• and
• wherein said image control means further includes a selection circuit operatively connected between said control circuit and said extended connector for selecting connection to either said driver/receiver or said extended slot.