Image reading apparatus in which an original image is automatically fed to a turntable

An image reading apparatus which receives an original cassette which stores an original to be read, said original being irradiated with illuminating light from an elongated light source and being read line-by-line by an array of light detecting elements disposed in a main scanning direction while said original is being scanned in an auxiliary scanning direction, said auxiliary scanning direction being perpendicular to said main scanning direction, said image reading apparatus comprising:

• a housing having a cassette insertion slot;
• an original table positioned in said housing for receiving and supporting the original cassette inserted through said cassette insertion slot;
• an auxiliary scanning mechanism attached to said original table for transporting the original cassette held on said original table in the auxiliary scanning direction;
• a trimming mechanism provided on said original table for transferring an unnecessary peripheral portion of the original out of sight by moving said original cassette held on said original table in a trimming direction along the main scanning direction;
• a rotating mechanism comprising a turntable mounted on said trimming mechanism for adjusting the angular position of the original cassette with respect to said trimming mechanism to a desired reading position;
• a positioning mechanism for positioning and fixing the original cassette at a predetermined position on said turntable where the original cassette is held perpendicular to an optical axis of the illuminating light, said positioning mechanism comprising guide means for guiding the original cassette to said predetermined position when said turntable is placed at an angular position where the original cassette can be installed on and removed from said turntable, lock means for locking the original cassette at said predetermined position, and an actuator for actuating said lock means to lock and release the original cassette;
• and
• a feed mechanism for automatically feeding the original cassette from said cassette insertion slot to said original table.