| 摘要 |
An optical head and an image forming apparatus are provided to prevent a temperature of a current drive type light emitting element from being greatly changed during a period when an image is formed. A plurality of unit regions in which a light emitting element(E), a control transistor(Tc), and a driving transistor(Tdr) are formed is repeatedly arranged in one direction. The light emitting element(E), driven by a current, emits light. The control transistor(Tc) is connected to the light emitting element(E) in parallel, and is turned off by receiving gray data designating a high gray for the light emitting element(E). The control transistor(Tc) is turned on by receiving gray data designating a low gray for the light emitting element(E). The driving transistor(Tdr) connects to the light emitting element(E) in series, and generates the current for driving the light emitting diode(E). Thermal resistance between the light emitting diode(E) in the unit region and the control transistor(Tc) formed in the unit region is lower than thermal resistance between the light emitting diode(E) and a control transistor formed in a unit region adjacent to the unit region.
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