Image reader apparatus and method of driving the same

A method of driving an image reader apparatus comprising a light source arranged so as to emit light to a document and an image sensor converting contrast between light and shade of an image on the document into an image signal, the method comprising:

• generating a synchronization signal synchronous with a timing of the document being fed and a feed cycle;
• activating a reading operation of the image sensor in synchronism with the synchronization signal;
• and
• turning the light source on in synchronism with the synchronization signal and turning the light source off so that a lighting period is equalized for each line irrespective of a variation of a cycle of the synchronization signal.

A scanner comprising a feeder device feeding a document and an image reader apparatus reading an image on the document being fed and outputting an image signal, wherein the image reader apparatus comprises:

• synchronization signal generator generating a synchronization signal synchronous with a feed timing and a feed cycle of the document;
• an image sensor reading an image on the document in synchronism with the synchronization signal;
• a light source emitting light;
• and
• lighting controller turning the light source on in synchronism with the synchronization signal and turning the light source off so that a lighting period is equalized for each line irrespective of a variation of a cycle of the synchronization signal.

A printer comprising a feeder device feeding a document and an image reader apparatus reading an image on the document being fed and outputting an image signal, wherein the image reader apparatus comprises:

• synchronization signal generator generating a synchronization signal synchronous with a feed timing and a feed cycle of the document;
• an image sensor reading an image on the document in synchronism with the synchronization signal;
• a light source emitting light;
• and
• lighting controller turning the light source on in synchronism with the synchronization signal and turning the light source off so that a lighting period is equalized for each line irrespective of a variation of a cycle of the synchronization signal.

A facsimile comprising a feeder device feeding a document and an image reader apparatuses reading an image on the document being fed and outputting an image signal, wherein the image reader apparatus comprises:

• synchronization signal g generator generating a synchronization signal synchronous with a feed timing and a feed cycle of the document;
• an image sensor reading an image on the document in synChronism with the synchronization signal;
• a light source emitting light;
• and
• lighting controller turning the light source on in synchronism with the synchronization signal and turning the light source off so that a lighting period is equalized for each line irrespective of a variation of a cycle of the synchronization signal.