Patent ID: 8416476

Claim:
An image reader capable of reading images on both sides of a document being conveyed, the reader comprising: a document path for guiding a document on a feed tray to a first delivery port; a first reading unit positioned on one side of the document path; the first reading unit being capable of reading at a first reading position an image on a first side of a document being conveyed along the document path; a second reading unit positioned on the other side of the document path; the second reading unit being adapted to read at a second reading position an image on a second side of a document being conveyed along the document path, the second reading position being either upstream or downstream from the first reading position; a first reading guide and a second reading guide so facing each other across the document path as to guide a document while images on the document are read at the first and second reading positions; the first and second reading guides defining therebetween a gap variable according to the thickness of a document; the first reading guide including a first guide member turnable around a first shaft extending across the document path, the first guide member being so positioned as to face a first side of a document; the second reading guide including a second guide member turnable around a second shaft extending across the document path, the second guide member being so positioned as to face a second side of a document; wherein, when a reference position is defined so that the distance between the first reading position and the reference position is equal to the distance between the second reading position and the reference position, in the relation to the reference position, the first shaft is positioned on the side where the first reading position is set and the second shaft is positioned on the side where the second reading position is set.