An image forming apparatus includes an image carrying member, a charging device, an exposure device, a developing device, a development voltage power supply, and a control section. The developing device includes a development container which contains a non-magnetic one-component developer and a developer carrying member which includes a rotary shaft and a roller portion stacked on the outer circumferential surface of the rotary shaft, and the resistance value of the roller portion is 9 to 11 [Log ?], and when the amount of toner conveyed on the developer carrying member is Md [g/m.sup.2], the amount of toner adhered on the image carrying member in a solid image is Mp [g/m.sup.2], the peripheral speed of the developer carrying member and the image carrying member are Sd [mm/sec] and Sp [mm/sec], 0.8?Sd/Sp<Mp/Md and 0.8?Sd/Sp?1.2 are satisfied.

A toner including polyester, wherein an amount of heat of a peak derived from the polyester in a range of from 40 C. through 70 C. during a cooling process is from 1.0 J/g through 15 J/g in differential scanning calorimetry performed under conditions below, <measuring conditions> after maintaining the toner at 20 C., heating the toner to 130 C. at 10 C./min (a first heating process), after maintaining the toner at 130 C. for 1 minute, cooling the toner to 50 C. at cooling speed of 10 C./min (the cooling process), and after maintaining the toner at 50 C. for 5 minutes, heating the toner to 130 C. at 10 C./min (a second heating process).

An image forming apparatus includes an image carrying member, a charging device, an exposure device, a developing device, a development voltage power supply, and a control section. The developing device includes a development container for containing a non-magnetic one-component developer composed only of a toner, a developer carrying member having an outer circumferential surface on which a toner layer is formed, and a toner supply member that supplies the toner to the developer carrying member. The control section performs control so that, as a cumulative drive time of the developing device increases, a supply voltage Vsdc becomes larger than a reference supply voltage and a development voltage Vdc becomes smaller than a reference development voltage, thus executing control to vary the development voltage Vdc and the supply voltage Vsdc so as to increase a potential difference VsdcVdc between the supply voltage Vsdc and the development voltage Vdc.

A developing device includes a developer bearing member, a developing container which accommodates developer, a conveying screw which conveys the developer accommodated in the developing container, and an inductance sensor which includes a detecting portion which detects magnetic permeability of the developer accommodated in the developing container. The conveying screw includes a rotary shaft, a blade which is spirally formed on an outer circumference of the rotary shaft, and a rib formed to protrude outwardly from the outer circumference of the rotary shaft. The rib is disposed opposite the detection portion with respect to a conveying direction of the conveying screw and is provided with a magnet, with magnetic flux density of the magnet being in the range of 20 mT to 60 mT.

A cartridge includes a pressing portion, a recessed portion, and an electrical contact. An apparatus body includes a contact unit that includes a contact and a protrusion. The contact and the protrusion are movable away from the mounting region against an elastic force. The contact unit is at a first position in a non-mounted state, a second position in a mounted state, and a third position in a middle state of transitioning from the non-mounted state to the mounted state. The second position is farther away from the mounting region than the first position by the protrusion being inserted into the recessed portion and the contact contacting with the electrical contact. The third position is farther away from the mounting region than the second position by the protrusion being pressed by the pressing portion so that the contact does not contact with the cartridge.

A transfer device includes a movable component, a moving assembly, a restrictor, and an operating member. The movable component moves toward and away from a latent image bearer unit. The moving assembly causes the movable component to move toward and away from the latent image bearer unit. The restrictor restricts the latent image bearer unit from detaching from an image forming apparatus. The operating member causes the moving assembly to move the movable component away from the latent image bearer unit and releases restriction of detachment of the latent image bearer unit from the image forming apparatus by the restrictor.

An image forming apparatus includes a developer; an image carrier on which a latent image is formed; a charge member that charges the image carrier; an exposure part that forms a latent image on the image carrier charged; a developer carrier that carries the developer and develops the latent image on the image carrier as a developer image; and a transfer part that transfers the developer image from the image carrier to a recording medium. The developer is a one-component based developer that is produced by a pulverization method and does not contain a charge adjuvant, and 0.25 (parts by weight) or more of a sol-gel silica to 100 (parts by weight) of a base particle as an external additive is added.

A region of an image bearing member facing a developer bearing member at a developing portion is set as a first region, a region of the image bearing member facing the developer bearing member at the developing portion after a region of the developer bearing member facing the first region makes one revolution is set as a second region, and a region of the image bearing member between the first region and the second region is set as a third region. A first pattern for performing exposure and a second pattern for not performing exposure or for performing exposure with an exposure amount smaller than an exposure amount used for the first pattern is formed in the third region. A length of the second pattern is larger than a length of the first pattern in a rotational direction, and the first pattern and the second pattern are repetitively formed.

An image forming apparatus includes an image carrying member, a charging device, an exposure device, a developing device, a development voltage power supply, and a control section. The developing device includes a development container which contains a non-magnetic one-component developer and a developer carrying member which includes a rotary shaft and a roller portion stacked on the outer circumferential surface of the rotary shaft, and the resistance value of the roller portion is 9 to 11 [Log ], and when the amount of toner conveyed on the developer carrying member is Md [g/m.sup.2], the amount of toner adhered on the image carrying member in a solid image is Mp [g/m.sup.2], the peripheral speed of the developer carrying member and the image carrying member are Sd [mm/sec] and Sp [mm/sec], 0.8Sd/Sp<Mp/Md and 0.8Sd/Sp1.2 are satisfied.

A developing roller having a conductive substrate and a resin layer present on the outer surface side of the substrate, wherein the developing roller is for a positive-charging toner, the resin layer contains a crosslinked urethane resin, an amino group is present at an outermost surface of the resin layer, where an ion intensity derived from the amino groups relative to all detected ions in the resin layer is 1.0% or more, a ratio of the total of detected values of Si, F, and Cl at the outermost surface of the resin layer is less than 5.0 Atomic %, and the elastic modulus and volume resistivity of the resin layer satisfy a specific relationship.