Patent ID: 8004550

Claim:
A light-emitting element head, comprising: a set of light-emitting element chips each having a plurality of light-emitting elements; a lighting signal supply unit that supplies the set of light-emitting element chips with a lighting signal for causing the plurality of light-emitting elements included in each of the light-emitting element chips to emit light; a first control signal supply unit that supplies a first control signal in common to the light-emitting element chips, the first control signal being a signal for sequentially specifying the plurality of light-emitting elements included in each of the light-emitting element chips one by one as a control target for controlling whether or not to emit light; a second control signal supply unit that supplies second control signals to the set of light-emitting element chips so that each of the second control signals is supplied in common to a plurality of light-emitting element chips belonging to each of N groups, each of the second control signals being a signal for giving an instruction to emit light or not to emit light to one of the light-emitting elements that is specified as the control target on the basis of the first control signal in each of the light-emitting element chips, the set of light-emitting element chips being divided into the N groups, where N is an integer of 2 or more; and a light-emission enable signal supply unit that supplies a plurality of light-emission enable signals to the set of light-emitting element chips so that the light-emission enable signals are supplied respectively to the plurality of light-emitting element chips belonging to each of the N groups, the light-emission enable signals being signals for allowing the set of light-emitting element chips to receive the second control signals, the light-emission enable signals being different from one another.