Patent ID: 7911664

Claim:
An image reader comprising: an image sensor including: plural sets of color image reading elements that read a part of an original, which is located at a first read target position of the image sensor, as a color image; and plural sets of monochrome image reading elements located at a different position than the plural sets of color image reading elements that read the part of the original, which is located at a second read target position of the image sensor different from the first read target position, as a monochrome image; a detection unit that detects at least one of: that the original to be read is present on an automatic document feeder; that a cover is open, the cover covering an original placement face where the original to be read is placed; and that the cover is closed; a carriage that includes the image sensor, the carriage being movable along a sub-scan direction during an image reading operation; a mode switch unit that switches between a color mode and a monochrome mode in accordance with a user's instruction; and a control unit, wherein: before the control unit accepts a start request by a user, when the mode switch unit switches to the color mode and when the detection unit detects that the original is present on the automatic document feeder, the control unit moves the carriage to a first position; before the control unit accepts a start request by a user, when the mode switch unit switches to the monochrome mode and when the detection unit detects that the original is present on the automatic document feeder, the control unit moves the carriage to a second position that is located a predetermined distance from the first position along the sub-scan direction; when the detection unit detects that the cover is open or closed and the mode switch unit switches to the monochrome mode, the control unit moves the carriage to a third position; and when the detection unit detects that the cover is open or closed and the mode switch unit switches to the color mode, the control unit moves the carriage to a fourth position that is located the predetermined distance from the third position along the sub-scan direction.