Patent ID: 7715066
Filing Date: 2010-05-11
Classification: H04N

Abstract:
1. A document reading apparatus comprising: a translucent plate; a platen that presses a document against the translucent plate; an illumination lamp that illuminates the document; a driving unit that drives the illumination lamp in a sub-scanning direction; an imaging element that reads the document in a main scanning direction, and line-outputs an image signal; an optical unit that projects a document image illuminated by the illumination lamp to the imaging element; an opening detector that detects a state of the platen whether the platen is “opened” at a level equal to or above a set opening degree or “closed” at a level less than the set opening degree; a reading controller that starts lighting of the illumination lamp in response to a change of the state of the platen from the “opened” to the “closed”; a rising detector that detects a rising of light intensity of the illumination lamp; and a size detector that reads the image signal of the imaging element after the rising detector detects a rising of the light intensity, determines a presence of the document in the main scanning direction, and decides a document size in the main scanning direction.