Light emitting element driving device for preventing that overcurrent flows through light emitting element

An image reading apparatus comprising:

• an imaging sensor to image a medium;
• and
• a plurality of light emitting devices to emit light having different colors to the medium, respectively, wherein
• each of the plurality of light emitting devices includes
• a light emitting portion to emit light in response to a supply of a first current,
• a first switch to turn ON/OFF the first current supplied to the light emitting portion,
• a second switch to turn ON/OFF a second current not supplied to the light emitting portion,
• a constant current circuit to adjust a total current amount of the first current and the second current to be constant, and
• a control circuit to control turning ON/OFF by the first switch and the second switch, and wherein
• the control circuit turns ON the first switch in a state of flowing the second current to the second switch by turning ON the second switch, and after turning ON the first switch, flows the first current to the light emitting portion and the first switch by turning OFF the second switch.