Image scanning device

An image scanning device, comprising:

• an image sensor that reads an image of an object, said image sensor comprising
• a plurality of image receiving elements aligned in a line, said image sensor outputting an image signal corresponding to a received image;
• a mirror that reflects light from said object towards said image sensor, said mirror being rotatable through a predetermined scanning range, around a predetermined axis which is parallel to said line, to deflect light from various portions of said object;
• a lens, arranged between said mirror and said image sensor, to form an image of said object on said image sensor;
• and
• a controller which performs a focusing detecting operation using said lens and said image sensor, said focusing detecting operation being performed when said mirror is oriented such that light from substantially a central portion of said scanning range is directed to said image sensor.

An image scanning device, comprising:

• an image sensor for reading an image of an object, said image sensor comprising a plurality of image receiving elements aligned in a line, said image sensor outputting an image signal corresponding to a received image;
• an optical system which forms an optical image of a portion of said object on said image sensor, a portion of said optical image of said object formed on said image sensor being varied through a predetermined range so that an image of said the object is captured;
• and
• a controller which performs a focusing detecting operation using said image sensor, said focusing detecting operation being performed using an image of substantially a central portion of said predetermined range.