Patent ID: 8755093

Claim:
An image reading apparatus comprising: a light source that irradiates light onto a document; a reading unit that receives light reflected from the document, converts the received light into electrical charges, and accumulates the electrical charges as an image signal; a moving unit that relatively moves the light source and the document; a moving speed control unit that controls a moving speed of the moving unit in accordance with a reading mode of the image reading apparatus to control a reading speed in the reading unit; and a turn-ON time control unit that controls the light source to be turned off in a given period based on the reading mode when the reading unit accumulates the electric charges so as to prevent the electrical charges accumulated in the reading unit from reaching a saturation amount, wherein the reading unit includes a semiconductor device that vertically and horizontally transfers the electrical charges accumulated by a charge coupled device to read out the electrical charges as the image signal, and the turn-ON time control unit sets the given period in which the light source is controlled to be turned off such that the given period begins after a beginning of a period during which the electrical charges are horizontally transferred and ends before an end of the period during which the electrical charges are horizontally transferred.