Patent ID: 7642535

Claim:
A light emitting device comprising: a plurality of light emitting elements that emit light to have luminosity depending on the magnitude of a driving signal; a plurality of holding units that are respectively disposed in the plurality of light emitting elements, and respectively hold the driving signal to maintain a magnitude regulated such that the luminosity of the plurality of light emitting elements becomes uniform; and a plurality of supply units that are respectively disposed in the plurality of light emitting elements, and supply the driving signal, which is held by the holding units to have a certain magnitude for a period of time according to a gradation of light to be emitted, to a corresponding light emitting element, the light emitting device further comprising: a plurality of integrated circuit chips that respectively has at least one of the plurality of holding units and at least one of the plurality of supply units; a control circuit chip that supplies a setting signal corresponding to the driving signal; a first substrate that includes at least a longer side, a first shorter side, and a second shorter side, the plurality of light emitting elements being arranged along the longer side of the first substrate, and the plurality of integrated circuit chips being arranged in a line along the plurality of light emitting elements; a second substrate on which the control circuit chip is fixed, the second substrate being connected to the first shorter side of the first substrate; and the setting signal being supplied from the first shorter side of the first substrate towards the second shorter side of the first substrate.