An image forming apparatus includes an acquisition interface, a developer, and a transferring and fixing device. The acquisition interface acquires image data. The developer supplies toner to an image carrier to form any one of a toner image according to the image data and a toner image of a certain shape pre-determined regardless of the image data. The transferring and fixing device forms an image represented by the image data on an image forming target medium by irradiating a surface of the medium having another surface adjacent to the toner image with light having at least a certain value of a transmittance with respect to the medium to transfer and simultaneously fix some or all of the toner image on the other surface of the medium by the light that is transmitted through the surface of the medium. The toner is melted by the light.

A development device includes a power source capable of applying a second voltage higher than a first voltage to be applied to a developer bearing member, a scattering prevention electrode that is arranged opposite the developer bearing member and to which the second voltage is applied from the power source, and a step-down circuit. The step-down circuit steps down a voltage from the power source from the second voltage to the first voltage to apply the stepped-down voltage to the developer bearing member.

A development device includes a power source capable of applying a second voltage higher than a first voltage to be applied to a developer bearing member, a scattering prevention electrode that is arranged opposite the developer bearing member and to which the second voltage is applied from the power source, and a step-down circuit. The step-down circuit steps down a voltage from the power source from the second voltage to the first voltage to apply the stepped-down voltage to the developer bearing member.

A development device includes a power source capable of applying a second voltage higher than a first voltage to be applied to a developer bearing member, a scattering prevention electrode that is arranged opposite the developer bearing member and to which the second voltage is applied from the power source, and a step-down circuit. The step-down circuit steps down a voltage from the power source from the second voltage to the first voltage to apply the stepped-down voltage to the developer bearing member.

A development device includes a power source capable of applying a second voltage higher than a first voltage to be applied to a developer bearing member, a scattering prevention electrode that is arranged opposite the developer bearing member and to which the second voltage is applied from the power source, and a step-down circuit. The step-down circuit steps down a voltage from the power source from the second voltage to the first voltage to apply the stepped-down voltage to the developer bearing member.

A high voltage generating device includes a booster and a driver. The booster includes first and second inductors connected in series and a capacitor connected in parallel to the first inductor. One end of the first inductor is connected to a DC voltage. The driver is connected in series to the second inductor and performs a switching operation by a driving signal. An inductance L2 of the second inductor is larger than an inductance L1 of the first inductor. The driver performs the switching operation at the driving frequency f of the driving signal within f0ff1. The f0 is a resonance frequency by the first inductor and the capacitor, and the f1 is a resonance frequency by the capacitor and the first and second inductors. The booster is driven by the driver and generates a sine wave AC high voltage higher than the DC voltage.

A developing roller includes a substrate having a conductive outer surface and a conductive layer on the outer surface of the substrate, an outer surface of the developing roller is formed of at least a first region and a second region having higher conductivity than the first region, the first region and the second region are placed adjacent to each other, the first region is placed on an outer surface of the conductive layer, the outer surface of the developing roller has an impedance of 1.010.sup.6 or more, and a potential of the outer surface of the developing roller satisfies a predetermined relationship.