Abstract: An exposure head includes: at least one light emitting element; an imaging optical system adapted to image light from the light emitting element; at least one reference element disposed to the light emitting element; and a control section adapted to control light emission of the light emitting element, and to put off the reference element in a latent image forming operation, wherein the control section obtains degree of deterioration of the light emitting element based on an intensity of light emitted by the light emitting element at timing other than timing when the latent image formation operation is executed and an intensity of light emitted by the reference element at the timing other than the timing when the latent image formation operation is executed, and controls light intensity of the light emitting element in the latent image forming operation based on the degree of deterioration.

Abstract: In order to improve the precision of liquid level computation in an accommodating part for accommodating a developer, the image forming device of the invention includes an accommodating part for accommodating a developer including a toner and a carrier, a developer container into which is supplied developer from the accommodating part, an electrostatic capacity detector for detecting electrostatic capacity, the electrostatic capacity detector having a first electrode provided to the accommodating part, a second electrode provided to the accommodating part, and a counter electrode opposite the first electrode and the second electrode, interposed by the developer; and a controller for stopping supply of developer from the accommodating part to the developer container based on a first electrostatic capacity detected by the first electrode and the counter electrode of the electrostatic capacity detector, and a second electrostatic capacity detected by the second electrode and the counter electrode.

Abstract: In order to provide a developer reservoir that allows the liquid level to be accurately detected and with which the device does not end up being bulkier, the developer reservoir of the present invention includes a holder for holding a liquid developer containing toner and a carrier, an electrostatic capacitance type of liquid level sensor that detects electrostatic capacitance and has a first sensor electrode provided to the holder and a second sensor electrode that is opposite the first sensor electrode with liquid developer in between, and a calculator for calculating the level of the liquid developer held in the holder on the basis of the electrostatic capacitance detected by the electrostatic capacitance type of liquid level sensor.

Abstract: An exposure head includes: at least one light emitting element; an imaging optical system adapted to image light from the light emitting element; at least one reference element disposed to the light emitting element; and a control section adapted to control light emission of the light emitting element, and to put off the reference element in a latent image forming operation, wherein the control section obtains degree of deterioration of the light emitting element based on an intensity of light emitted by the light emitting element at timing other than timing when the latent image formation operation is executed and an intensity of light emitted by the reference element at the timing other than the timing when the latent image formation operation is executed, and controls light intensity of the light emitting element in the latent image forming operation based on the degree of deterioration.