An image forming apparatus includes a rotatable photosensitive member (drum), a first corona charger, a second corona charger, an image forming portion, a voltage applying portion, a surface potential detecting portion, a controller. The controller determines a condition of voltages applied to the first and second corona chargers during image formation, by setting a first voltage condition for the first corona charger so that the surface potential of the drum is a second potential lower in absolute value than the first potential in a state in which the first corona charger operates, and the second corona charger does not operates, and then by setting a second voltage condition for the second corona charger so that the surface potential of the drum is the first potential in a state in which the first corona charger operates under the first voltage condition, and the second corona charger operates.

An image forming apparatus includes a rotatable photosensitive member (drum), a first corona charger, a second corona charger, an image forming portion, a voltage applying portion, a surface potential detecting portion, a controller. The controller determines a condition of voltages applied to the first and second corona chargers during image formation, by setting a first voltage condition for the first corona charger so that the surface potential of the drum is a second potential lower in absolute value than the first potential in a state in which the first corona charger operates, and the second corona charger does not operates, and then by setting a second voltage condition for the second corona charger so that the surface potential of the drum is the first potential in a state in which the first corona charger operates under the first voltage condition, and the second corona charger operates.

An interlock power supply stops supplying a voltage if AC power supply is supplying AC voltage and an interlock condition is satisfied, and supplies a voltage if AC power supply is supplying AC voltage and the condition is not satisfied. A non-interlock power supply supplies a voltage independently of the condition, if AC power supply is supplying AC voltage. A first wiring pattern that connects an interface and a switch drive circuit. A second wiring pattern is connected to the non-interlock power supply. A constant-voltage element is provided between a first section of the first wiring pattern and a second section of the first wiring pattern.

An image forming apparatus includes a latent-image forming unit that forms an electrostatic latent image onto an image carrier, a developing member that develops the electrostatic latent image held on the image carrier with a developer, a container that contains the developer supplied to the developing member, a stirring member that stirs the developer by rotating in the container, a density detecting unit that is disposed in the container and that detects a density of the developer, and a switching unit that switches an image formation condition by using a period of a signal output by the density detecting unit.

An image forming apparatus includes a latent-image forming unit that forms an electrostatic latent image onto an image carrier, a developing member that develops the electrostatic latent image held on the image carrier with a developer, a container that contains the developer supplied to the developing member, a stirring member that stirs the developer by rotating in the container, a density detecting unit that is disposed in the container and that detects a density of the developer, and a switching unit that switches an image formation condition by using a period of a signal output by the density detecting unit.

An interlock power supply stops supplying a voltage if AC power supply is supplying AC voltage and an interlock condition is satisfied, and supplies a voltage if AC power supply is supplying AC voltage and the condition is not satisfied. A non-interlock power supply supplies a voltage independently of the condition, if AC power supply is supplying AC voltage. A first wiring pattern that connects an interface and a switch drive circuit. A second wiring pattern is connected to the non-interlock power supply. A constant-voltage element is provided between a first section of the first wiring pattern and a second section of the first wiring pattern.

A charge storage cell includes a substrate having a back side conductive layer or conductive element, a top side metal pad coupled to the substrate, and an insulating layer formed on the metal pad. The metal pad will support an electric charge injected through the insulating layer by a charged particle beam. A regular array of charge storage cells provides a charge storage array.

An image forming apparatus includes a latent-image forming unit that forms an electrostatic latent image onto an image carrier, a developing member that develops the electrostatic latent image held on the image carrier with a developer, a container that contains the developer supplied to the developing member, a stirring member that stirs the developer by rotating in the container, a density detecting unit that is disposed in the container and that detects a density of the developer, and a switching unit that switches an image formation condition by using a period of a signal output by the density detecting unit.

An image forming apparatus includes a latent-image forming unit that forms an electrostatic latent image onto an image carrier, a developing member that develops the electrostatic latent image held on the image carrier with a developer, a container that contains the developer supplied to the developing member, a stirring member that stirs the developer by rotating in the container, a density detecting unit that is disposed in the container and that detects a density of the developer, and a switching unit that switches an image formation condition by using a period of a signal output by the density detecting unit.

A charge storage cell includes a substrate having a back side conductive layer or conductive element, a top side metal pad coupled to the substrate, and an insulating layer formed on the metal pad. The metal pad will support an electric charge injected through the insulating layer by a charged particle beam. A regular array of charge storage cells provides a charge storage array.