Optical print head and image forming apparatus

摘要

An optical print head performs optical writing onto target, and includes: current-driven light-emitting elements arranged in rows in a predetermined direction; driving transistors that are each electrically series-connected with the light-emitting elements in one-to-one correspondence, and each supply a driving current to a corresponding light-emitting element; a current control unit that controls, for each light-emitting element, a driving current amount in accordance with variation in light-emitting properties of the light-emitting element that indicate relation between the driving current amount and a light amount emitted by the light-emitting element; an application unit that, upon receiving electrical power supplied from an external power source, applies application voltage to circuits each consisting of a light-emitting element and a corresponding driving transistor; and a voltage control unit that suppresses variation in divided voltage applied to each driving transistor by controlling the application unit to apply increased application voltage of the driving current amount increases.

主权项

1. An optical print head that performs optical writing onto a target, the optical print head comprising:
a plurality of current-driven light-emitting elements that are arranged in rows in a predetermined direction; a plurality of driving transistors that are each electrically series-connected with the light-emitting elements in one-to-one correspondence, and each structured to supply a driving current to a corresponding one of the light-emitting elements; a current control unit structured to control, for each of the light-emitting elements, an amount of the driving current in accordance with variation in light-emitting properties of the light-emitting element, the light-emitting properties indicating a relation between the amount of the driving current and an amount of light emitted by the light-emitting element; structured to, upon receiving electrical power supplied from an external power source, apply an application voltage to a source or a drain of each of the plurality of driving transistors; a voltage control unit structured to vary the application voltage such that the application voltage is repeatedly increased as the amount of the driving current increases.