Light emitting device and image forming apparatus including light emitting device

An image forming apparatus comprising:

• a photosensitive member for being rotationally driven about a rotational axis, the photosensitive member including a photosensitive member surface;
• an exposure head including a light emitting device, a circuit board on which the light emitting device is mounted, and a lens array for guiding light emitted from the light emitting device to the photosensitive member surface;
• and
• a controller for outputting image data for driving the light emitting device, to the circuit board,
• wherein the light emitting device comprises:
• a silicon wafer including a driving circuit for driving the light emitting device;
• and
• a laminar member including a first electrode layer that includes a plurality of electrodes arranged in a direction substantially parallel to the rotational axis of the photosensitive member, a second electrode layer through which light is transmittable and which is laminar, and a light emitting layer formed in a layer between the first electrode layer and the second electrode layer and for emitting light by application of a voltage, the laminar member being formed on a surface of the silicon wafer, and
• wherein the driving circuit includes a voltage generating circuit for generating a driving voltage and a pulse signal generating circuit for generating a pulse signal for each of the plurality of electrodes on the basis of the image data, and the driving circuit applies the driving voltage, generated by the voltage generating circuit, to each of the plurality of electrodes depending on the pulse signal.