G03G2215/021

Cleaning member, charging device, and image forming apparatus
10423092 · 2019-09-24 · ·

A cleaning member includes a first cleaning part formed of a porous material and a second cleaning part formed of a porous material. The first cleaning part includes first projections each having a size that enables the first projections to pass between projecting portions of an object to be cleaned having surface irregularities and to reach the bottom of recessed portions of the object to be cleaned. The second cleaning part includes second projections larger than the first projections. The cleaning member cleans the object to be cleaned by coming into contact with the object to be cleaned.

Image forming apparatus
10394155 · 2019-08-27 · ·

An image forming apparatus includes a movable photosensitive member, a charging roller, an electrostatic image forming portion, a developing sleeve, a charging voltage source, a charging voltage conducting path, a developing voltage source, a developing voltage conducting path, and a capacitor electrically connected between an output terminal of the charging voltage source and a ground potential or between the charging voltage conducting path and the ground potential. The capacitor satisfies the following relationship: {C1/(C1+C2)}Vpp5 (V), where C1 (pF) is electrostatic capacity formed by the first and second conducting paths, C2 (pF) is electrostatic capacity of the capacitor, and Vpp (V) is a peak-to-peak voltage of the AC component of the developing voltage.

IMAGE FORMING APPARATUS

Rotation of an image bearing member is started and stopped in a contact state between the image bearing member and a developing member. During post-rotation operation, a controller ends application of a charging voltage after changing the charging voltage stepwise to first and second charging voltages. The controller ends application of a developing voltage after changing the developing voltage stepwise at a developing position to first and second developing voltage in synchronism with the first and second charging voltages. A potential difference between each of surface potentials of first and second regions and an associated one of the first and second developing voltages is maintained within a predetermined range. The controller carries out control so that an absolute value of the surface potential of at least one of the first and second regions is made small by passing a current under application of a transfer voltage.

Charging member having two surface layers

An example charging member has a conductive support, a conductive elastic body layer on the conductive support, a first surface layer on the conductive elastic body layer, and a second surface layer on the first surface layer. The first surface layer includes a binder resin and a first plurality of first particles dispersed in the binder resin of the first surface layer, the second surface layer includes the binder resin, a second plurality of first particles, and second particles, the second plurality of first particles and the second particles being dispersed in the binder resin of the second surface layer, and an average diameter d.sub.1 of the first particles is 3 ?m?d.sub.1?6 ?m and an average diameter d.sub.2 of the second particles is 20 ?m?d.sub.2?26 ?m.

CONDUCTIVE ROLLER
20190187581 · 2019-06-20 · ·

Provided is a conductive roller in which the occurrence of an image defect caused by a pressure mark is suppressed. In this conductive roller, plural resin layers are arranged on the outer circumference of a shaft 4. The resin layers include at least a base layer 1 and a surface layer 3 from the inner circumferential side. The plural resin layers all have a loss tangent (tan ) of 0.2 or less at a temperature of 40 C. and, among the plural resin layers, at least a pair of two adjacent layers satisfy a relationship of GoGi between the elastic modulus Go of a layer positioned on the outer circumferential side and the elastic modulus Gi of a layer positioned on the inner circumferential side.

Image forming apparatus and cartridge having charging roller

An image forming apparatus includes a photosensitive member having a surface having elastic deformation power of 47% or more, a charging roller forming a nip between itself and the photosensitive member, and an image forming portion. When a nip region corresponding to the nip is formed and then an area of independent contact portions between the charging member and a measuring contact member is measured, the following relationship is satisfied: (contact width X)(Contact area ratio )0.1, where a length from a position of one end to a position of the other end of the nip region with respect to a direction perpendicular to a longitudinal direction of the charging roller is the contact width X, and a ratio of a sum of areas of the independent contact portions to an entire area of a measuring region is the contact area ratio .

Image forming apparatus that controls cleaning ability of cleaner and control method thereof

An image forming apparatus configured to, in a case where a difference between a charging current flowing through a first charging roller and a charging current flowing through a second charging roller is larger than a first threshold value, perform first cleaning processing in which a cleaning ability of one cleaner of a first cleaner and a second cleaner, which corresponds to one of the first charging roller and the second charging roller, is lower than a cleaning ability of another cleaner of the first cleaner and the second cleaner, which corresponds to another of the first charging roller and the second charging roller, a charging current flowing through the one charging roller being larger than a charging current flowing through the other charging roller.

Charging roller, cartridge, image forming apparatus and manufacturing method of the charging roller

A charging roller includes a surface layer containing first and second surface particles and satisfying the following:
6.0 (m)Rz18.8 (m),i
where Rz is a ten-point average roughness (m) of a charging roller surface,
7 (m)d20 (m),ii
where d is a thickness (m) of the surface layer,
9.8 (m)D115.8 (m) and 2.8 (m)D25.2 (m),iii
where D1 and D2 are average particle size (m) of the first surface particles, and the second surface particles, respectively,
3.0D1/D25.6, andiv
0.10M1/(M1+M2)0.32,v
where M1 is a total weight (mg) of the first surface particles per unit area of the charging roller surface, and M2 is a total weight (mg) of the second surface particles per unit area of the charging roller surface.

CLEANING MEMBER, CHARGING DEVICE, AND IMAGE FORMING APPARATUS
20190094742 · 2019-03-28 · ·

A cleaning member includes a first cleaning part formed of a porous material and a second cleaning part formed of a porous material. The first cleaning part includes first projections each having a size that enables the first projections to pass between projecting portions of an object to be cleaned having surface irregularities and to reach the bottom of recessed portions of the object to be cleaned. The second cleaning part includes second projections larger than the first projections. The cleaning member cleans the object to be cleaned by coming into contact with the object to be cleaned.

CONDUCTIVE ROLLER, AND PRODUCTION METHOD THEREFOR
20190041766 · 2019-02-07 · ·

Provided are: a conductive roller in which detachment and scraping of particles from a surface layer are unlikely to occur; and a method of producing the same. A conductive roller 10 includes: a shaft 1; and an elastic layer 2 and a surface layer 3, which are sequentially formed on the outer circumference of the shaft 1. In this conductive roller 10, the surface layer 3 is composed of a mixture of a surface layer resin composition and particles, the surface layer resin composition contains a heat-curable or energy ray-curable urethane resin, and the particles are composed of a particle resin composition containing a urethane (meth)acrylate.